
S/^rdZ 



Glass. 

Book ijz^ 



U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ENTOMOLOGY— BULLETIN No. 98. 

L. O. HOWARD, Entomologist and Chief of Bureau. 



HISTORICAL NOTES ON THE CAUSES 
OF BEE DISEASES. 



BY 



E. F. PHILLIPS, Ph. D., 

In Charge of Bee Culture, 



AND 



G. F. WHITE, Ph. D., M. D., 

Expert in Bacteriology. 



Issued March 26, 1912. 




WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 

1912. 



I 



U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ENTOMOLOGY— BULLETIN No. 98. 

L. O. HOWARD, Entomologist and Chief of Bureau. 



HISTORICAL NOTES ON THE CAUSES 

OF BEE DISEASES. 



BY 



E. P. PHILLIPS, Ph. D., 

In Charge of Bee Culture, 



AND 



G. F. WHITE, Ph. D., M. D., 

Expert in Bacteriology. 



Issued March 26, 1912. 




WASHINGTON: 

GOVERNMENT PRINTING OEEIOE. 

1912. 






TX 



S F53* 
-p5"\ 



5 J7.RE4 U OF ENTOMOLOGY. 

L. 0. Howard, Entomologist and Chief of Bureau. 

C. L. Marlatt, Entomologist and Acting Chief in Absence of Chief. 

R. S. Clifton, Executive Assistant. 

W. F. Tastet, Chief Clerk. 

F. H. Chittenden, in charge of truck crop and stored product insect investigations. 

A. D. Hopkins, in charge of forest insect' investigations. 

W. D. Hunter, in charge of southern field crop insect investigations. 

F. M. Webster, in charge of cereal and forage insect investigations. 
A. L. Quaintance, in charge of deciduous fruit insect investigations. 
E. F. Phillips, in charge of bee culture. 

D. M. Rogers, in charge of preventing spread of moths, field work. 
Rolla P. Currie, in charge of editorial work. 
Mabel Colcord, in charge of library. 

Investigations in Bee Culture. 
E. F. Phillips, in charge. 

G. F. White, J. A. Nelson, experts. 

G. S. Demuth, A. H. McCray, N. E. McIndoo, apicultural assistants. 

Pearl H. Garrison, preparator. 

H. A. Surface, D. B. Casteel, collaborators. 

2 



ft w % 



LETTER OF TRANSMITTAL 



U. S. Department of Agriculture, 

Bureau of Entomology, 

Washington, D. C, September 27, 1911. 
Sir: I have the honor to transmit herewith a manuscript entitled 
1 'Historical Notes on the Causes of Bee Diseases/' prepared by Drs. 
E. F. Phillips and G. F. White, of this bureau. The investigations 
of the causes of bee diseases are highly important in the control of 
these maladies. Many of the papers on this subject are not available 
and many also record errors in observations and conclusions. The 
purpose of the present paper is to assist bee keepers in obtaining a 
proper understanding of the work done by the various investigators 
whose papers are discussed. I respectfully recommend the publica- 
tion of this manuscript as Bulletin No. 98 of this bureau. 
Respectfully, 

L. O. Howard, 
Entomologist and Chief of Bureau. 
Hon. James Wilson, 

Secretary of Agriculture. 

3 



CONTENTS 



Page. 

Introduction 11 

American foul brood 11 

European foul brood 12 

The BO-called " pickled brood " 12 

Paralysis 13 

Dysentery 13 

Isle of Wight disease 13 

Consideration of papers on the causes of bee diseases 13 

Schirach, 1771 13 

Leuckart, November 12, 1860 14 

Molitor-Muhlfeld, April 15, 1868 14 

Preuss, October 1, 1868 15 

Schonfeld, November 15, 1873 16 

Dzierzon, 1882 18 

Cheshire, August 1, 1884 18 

Cheshire, August 15, 1884 21 

Cheshire, September 1, 1884 22 

Cheshire, September 15, 1884 24 

Cheshire, October 15, 1884 25 

Cheshire and Cheyne, August, 1885 25 

Cheyne, August, 1885 29 

McLain, 1887 35 

McLain, 1888 37 

Lortet, February, 1890 38 

Mackenzie, December, 1892 39 

Howard, March 1, 1894 41 

Howard, September 10, 1896 42 

Howard, February 15, 1900 44 

Harrison, December, 1900 48 

Lambotte, September 25, 1902 53 

Harrison, February 28, 1903 56 

Moore and White, January 15, 1903 58 

White, January 15, 1904 61 

Bahr, 1904 64 

Burri, October and November, 1904 64 

White, January 14, 1905 66 

White, June, 1905 67 

Wilson, 1905 67 

Burri, January, 1906 68 

Maassen, June, 1906 72 

Maassen, June, 1906 73 

Bahr, 1906 74 

Phillips, October 3, 1906 75 

Erne, November, 1906 75 

5 



6 HISTORICAL NOTES ON BEE DISEASES. 

Consideration of papers on the causes of bee diseases — Continued. Page. 

White, November 6, 1906 76 

Maassen, February, 1907 78 

Imms, June, 1907 79 

White, July 29, 1907 80 

Phillips, December 31, 1907 82 

Maassen, 1908 82 

Maassen, September, 1908 85 

White, December 26, 1908 85 

Maiden, February, 1909 87 

Zander, August, 1909 89 

Maassen, March, 1910 91 

Maassen and Nithack, March, 1910 92 

Maiden, June, 1910 92 

Zander, 1910 93 

' Zander, 1911 93 

Brief chronological summary of the work on the causes of bee diseases 93 

The different diseases that attack bees 93 

The causes of bee diseases '. 94 

Index. _ 95 



PEEFAOE. 



Bees, like many other members of the animal kingdom, are 
known to suffer from diseases. Simultaneously with the good work 
that has been done during the last half century toward the deter- 
mination of the causes of the various diseases of man and animals, 
there has been some work done on the causes of bee diseases. This 
work has caused considerable literature to be written on the subject. 
Although this literature contains much that is valuable, it abounds 
in statements that are erroneous and in conclusions that seem 
unjustifiable. Many of the inaccurate statements and conclusions 
have been frequently copied in the past and they are still too often 
copied into the current literature on bee diseases. The bee keeper, 
therefore, in reading is often at a loss to know what is true and 
what is untrue; what is actually known and what is not known. 

For the purpose of aiding the bee keepers with this literature, 
we have reviewed here portions oi several original papers dealing 
with the causes of bee diseases. It is hoped that this bulletin may 
serve as a means whereby the bee keeper may solve for himself 
some of the apparent mysteries found in beekeeping literature. 

In selecting the papers for review, for the most part, those were 
chosen which were written by men who had worked more or less 
on the causes of bee diseases. The reviews that have been made 
contain the more important beliefs concerning the causes of these 
diseases that were entertained by the authors of the different papers 
at the time they wrote. The classification of the diseases of bees as 
understood by these different men is also frequently included. The 
original papers naturally contain much that has not been mentioned 
in these brief reviews, and therefore the reader is urged, if oppor- 
tunity permits, to read the papers cited in this bulletin rather than 
the reviews. It is probable that the papers here considered might 
with profit have been more completely reviewed and that other papers 
might with profit have been considered, but if either had been done 
it is probable that the length of the bulletin would have defeated its 
object. 

It is hoped that the readers of bee-disease literature will learn, so 
far as possible, to judge correctly an article that discusses in any 
way the causes of bee diseases. To do this., one should first of all 
learn who are actually doing work on the causes of these diseases. 

7 



8 HISTORICAL NOTES ON BEE DISEASES. 

The writings of all these men should be read. If an investigator 
has done work on the causes of other diseases than bee diseases, but 
chooses to write on bee diseases, the reader will usually profit by 
reading his papers. The great mass of literature, on the other 
hand, created by those who have not worked on the cause of any 
disease can as a rule with profit be rejected. 

Having determined whose papers should be read, the character 
of the work of each investigator should be carefully noted. If the 
character of a man's work proves to be good, give weight to all his 
statements, but if the character of a man's work is poor, expect 
untrue statements and erroneous conclusions. If one will learn in 
this way to judge the different papers, one will soon know what to 
believe and what to suspect, but if one does not learn to do this he 
will be forever at the mercy of printed pages. 

As the reader forms his opinion of the character of the work done 
by the different men referred to in this bulletin, permit the sugges- 
tion that he exercise some leniency inasmuch as the time at which 
a man works and the circumstances under which he labors are 
frequently in a measure responsible for mistakes. The reader will 
note, however, that many times the mistakes made in the study of 
bee diseases have been made only because insufficient and careless 
work was done by the investigator. In such cases no leniency is to 
be exercised in arriving at conclusions. 

The writers of this bulletin have commented very little on the 
character of the work done by the different authors of the papers 
reviewed. The views of these men as they are found in the papers 
are given and the reader is allowed and urged to judge for himself 
whether or not such views are true. To aid the reader, however, 
the writers have made a few suggestions when it was thought that 
they might prove advantageous. The page references refer to pages 
in this bulletin. 

In reading a paper there is always the danger of misinterpreting 
an author's conception. This danger is greatly increased if the 
author of the paper criticized uses a foreign language. Realizing 
this possible source of error, we have endeavored in every case to be 
cautious. When quotations from papers written in a foreign lan- 
guage were selected, rather free translations of them into English 
have been made. 

We disagree with a very large number of the statements which 
have been made by different authors referred to in this bulletin con- 
cerning the causes of bee diseases. Therefore let it be emphasized 
that the reviews which are here made are intended to express the 
opinion of the author of the paper reviewed, and not by any means 
the opinion of the writers of this bulletin. 



PREFACE. 9 

To entomologists who feel an interest in the causes of insect dis- 
eases and who wish to be able to judge with some satisfaction the 
work that has been and is being done on insect diseases this bulletin 
will be of special interest. It is believed that by the learning of the 
mistakes made by workers on bee diseases, and by the learning of 
the causes for such mistakes, the careful reader will be enabled to 
judge more accurately the value of the various reports that appear 

on the diseases of insects. 

The Authors. 



HISTORICAL NOTES ON THE CAUSES OF BEE DISEASES. 



INTRODUCTION". 

Bee keepers, as a rule, manifest a keen desire to know about the 
causes of bee diseases and they show a lively interest in the investiga- 
tions leading to the determination of the causes. This is gratifying 
to those working on these diseases and will be a great benefit to 
the apiarist who must treat the diseases. The losses to apiculture 
from diseases are enormous, and inasmuch as the successful treat- 
ment of a disease depends largely upon a knowledge of the cause of 
the disease to be treated it behooves every owner of an apiary to 
become as f amiliar as' possible with the causes of bee diseases. 

The facts that are known about the causes of bee diseases unfor- 
tunately are altogether too few. As this can be said of all diseases 
affecting the animal kingdom, the bee keeper has no cause for despair. 
An attempt, however, will be made in this bulletin to furnish data 
from which the bee keeper may be able to inform himself concerning 
the facts that are really known about the causes of bee diseases. 

In this introduction it might be well to classify the bee diseases as 
the writers of this bulletin understand them. Bee diseases can be 
conveniently classified under those affecting the brood and those affect- 
ing the adult bee. The most important brood diseases are American 
foul brood, European foul brood, and the so-called "pickled brood/' 
The disorders affecting adult bees that are of most importance are 
being referred to at present under the names of paralysis, dysentery, 
and Isle of Wight disease. 

American foul brood. — American foul brood is a very widely dis- 
tributed disease and better known to bee keepers than European foul 
brood. It is the one which is generally referred to by the bee keeper 
at the present time when he speaks of "foul brood. " The brood 
affected with this disease is usually capped before it dies. The 
color of the dead brood presents in general various shades of brown. 
The marked ropiness of the decaying remains of the dead larvae is 
probably the most characteristic and well-known feature of the dis- 
ease. The punctured cappings, the scales formed from dried-down 
larvae, and the disagreeable odor sometimes present are aids to its 
diagnosis. This disease is clearly an infectious one. The exciting 
cause of it is a bacterium known as Bacillus larvse. 

11 



12 HISTORICAL NOTES ON BEE DISEASES. 

European foul brood. — European foul brood is the disease which 
Cheshire and Cheyne (p. 25) described in their studies of foul brood. 
Howard (p. 44), of Texas, made a very brief and unsatisfactory 
study of this disease at one time and named it "New York bee dis- 
ease" or "black brood." We are strongly inclined to believe that 
Burri (p. 68) was working with this disease for the most part during 
his study of the condition which he refers to as "sour brood." Euro- 
pean foul brood is less widely distributed in this country than is 
American foul brood. In European foul brood one finds, as a rule, 
most of the diseased brood as yet uncapped. In general, the brood 
dead of this disease presents various shades of yellow. Usually there 
is no ropiness; at times, however, there is. That degree of ropiness, 
however, which is so characteristic of American foul brood is seldom 
present in European foul brood. There is frequently a slightly sour 
odor to the diseased brood. The rapidity with which this disease 
spreads in a new territory and the marked destructiveness of it are 
features which most bee keepers have experienced who have been 
so unfortunate as to have the malady affect their apiary. The dis- 
ease is clearly, therefore, an infectious one. The exciting cause is 
not known. Claims are made by some that certain species of bacte- 
ria stand in direct etiological relation to the disease, but satisfactory 
evidence to prove such contentions are wanting. 

The so-called "piclcled brood." — Howard (p. 42), of Texas, described 
what he chose to call pickled brood. His findings have never been 
confirmed. The name " pickled brood," however, is very frequently 
used by bee keepers in referring to a diseased condition of the brood. 
Howard's description of "pickled brood" (p. 43), however, does not 
apply to such a condition. Since the name "pickled brood" is not 
accurately applied and is, moreover, entirely inappropriate for the 
condition which we find, we prefer for the present to use the expres- 
sion " so-called pickled brood." In this condition the brood dies 
about the time of capping. The body wall of the larva, in a case 
which might be called typical, is intact and rather tough. When 
this wall is broken, one often finds a watery content in which is sus- 
pended a granular substance. As a rule a very small proportion of 
the brood is affected. The disease does not seem to be infectious. 
The loss to the colony in comparison with European foul brood and 
American foul brood is slight. This disorder, therefore, should 
arouse no great amount of fear. While the number of colonies lost 
from this disease is comparatively small, in the aggregate many bees 
die as a result of the condition. The disease has a very wide dis- 
tribution. The exciting cause is not known. 

There is very little that is definitely known about the diseases of 
adult bees. They have not been sufficiently investigated to make it 
possible to classify them with any degree of satisfaction. 



SCHIRACH, 1771. 13 

Paralysis. — But little is definitely known about paralysis of bees. 
The disease has not been demonstrated to be infectious. Many sup- 
positions have been made by different writers as to the cause of the 
trouble, but no satisfactory evidence has been produced to prove the 
cause. 

Dysentery. — A condition known as dysentery has often been 
observed by the bee keeper. But little is known about the disorder. 
There is considerable evidence that the nature of the winter food 
plays a part in its causation. Zander (p. 89) has recently suggested 
that there are two forms of this affection, a noninfectious one and 
an infectious one. To an infectious form he ascribes Nosema apis 
as a cause. Much work must yet be done upon this condition. 

Isle of Wight disease. — The disorder known as Isle of Wight dis- 
ease was first reported from the Isle of Wight by Imms (p. 79). 
Maiden (p. 93) reports that the disease has more recently spread to 
the mainland (England). This disorder has so far not been found 
in any other country. The cause has not been definitely established. 

It is urged that the reader peruse the preface to this bulletin 
(pp. 7-9) carefully. By so doing the intent of the writers of this bul- 
letin will be better understood and the chances of misinterpretation 
will be lessened. 

CONSIDERATION OF PAPERS ON THE CAUSES OF BEE DISEASES. 

SCHIRACH, 1771. 

Schirach 1 in 1771 classified the diseases which most frequently 
attack bees as follows: (1) Dysentery; (2) disease of the antennae; 
(3) foul brood; (4) queens laying drone eggs only; (5) sterile queen; 
(6) queenless colonies. 

Dysentery he considered to be dietary in origin. No belief is 
expressed as to the cause of the disease of the antennas, to which 
he refers, but he states that with this disease the danger is not great. 
The disease which he designates as foul brood, however, he believed 
to be quite dangerous, very fatal, and a true pest after it has reached 
a certain stage. To this condition he attributed two causes, one 
cause being ascribed to the improper food which was consumed by 
the larvas, and the other being a fault of the queen in permitting 
the brood to be so arranged in the cells that the heads point inward. 
Considering these two widely different causes ascribed to an abnor- 
mality in the brood, one might suspect that there was more than 
one disease in the condition which he designated as foul brood. 
That part of the disease condition, to which as a cause he ascribed 
the food, could well be an infectious disease — either American foul 

i Schirach, A. G., 1771. Histoire naturelle de la reine des abeilles, avec Tart de former des essaims. 
La Haye. Pp. Lxm+269; 3 plates. 



14 HISTORICAL NOTES ON BEE DISEASES. 

brood or European foul brood. The other form of the disease, in 
which the brood was supposed to be placed with the head directed 
inward, most probably was not an infectious disease. In the treat- 
ment of foul brood Schirach recommends the removal of all combs 
from the bees. This principle is the one upon which is based the 
methods which are most successful at the present time in the treat- 
ment of the infectious brood diseases. 

The other abnormalities in the colony which are mentioned in 
the paper relate to the condition of the queen. These are conditions 
familiar to the bee keeper, but which may occur more often when an 
infectious brood disease is present. Mention is also made of the fact 
that brood is sometimes killed by chilling. Schirach refers to this 
as an accident and not as a disease. 

Leuckart, November 12, 1860. 

Leuckart * had entertained the opinion that infectious foul brood 
was due to a fungus, and he felt that his view was strengthened by 
some work which was done on the diseases of the silkworm. During 
the summer of 1860, however, he had an opportunity to see much 
infectious foul brood in samples of comb and in colonies. In the 
diseased material he found no fungi that he could not attribute to 
the phenomenon of decay. He states in the paper that foul brood 
is obviously a collective name that includes various forms of disease 
with the features in common of being epidemic, attacking early 
stages, and being usually fatal. One sample was examined, and a 
number of diseased and dead larvae was found to contain an uniden- 
tified fungus. The majority of them, however, did not contain the 
fungus; yet these latter larvae were thought to be dying of the usual 
type of foul brood. From his summers' experiences Leuckart ar- 
rived at the conclusion that the infectious foul brood was not due to 
a fungus. 

MOLITOR-MtJHLFELD, APRIL 15, 1868. 

Molitor-Muhlfeld 2 in 1868 reported some startling observations 
relative to the cause of foul brood. He writes that foul brood is of 
two kinds, the mild kind and the so-called infectious or virulent one. 
The mild form of foul brood, according to his views, resulted from a 
chilling of the brood. During the early warm days of spring, he 
argues, brood rearing is stimulated to such an extent that when 
colder weather follows it is impossible for the bees to care for all the 
brood, and as a result the neglected brood is chilled, dies, and be- 

1 Leuckart, Dr., November 12, 1860. Zur Naturgeschichte der Bienen. 3. Zur Kenntniss der Faul- 
brut und der Pilzkrankheiten bei den Bienen. Eichstadt Bienenzeitung, 16 Jahrg., Nro. 20, pp. 232-233. 

2 Molitor-Muhlfeld, April 15, 1868. Die Faulbrut, ihre Entstehung, Fortpflanzung und Heilung. Eich- 
stadt Bienenzeitung, 24 Jahrg., Nro. 8, pp. 93-97, 



PREUSS, OCTOBER 1, 1868. 15 

comes foul. From this condition, this author stated, no danger is 
to be feared, as the bees afterward remove all this dead brood, leav- 
ing the colony free from danger. The cause of the virulent form of 
foul brood is attributed by Molitor-Muhlfeld to a small parasitic 
ichneumon fly, reddish-yellow in color and scarcely one-sixth of an 
an inch long, to which he gave the name Ichneumon apium mellifi- 
carium. He writes that this fly had already been observed about 
foul-brood colonies by another writer, but that it was thought to be 
a carrion fly. Concerning the life history of these flies, he says that 
they press into the hives and lay their eggs in the bee larvae. The 
larvae live in spite of this until the cell is capped and the cocoon is 
spun. During this time the fly larvae feed upon the fat of the bee 
larvae, and finally bore their way out of the body into the cell, undergo 
metamorphosis, and in a few days escape from the cells through 
openings which they make in the center of the cell-capping. These 
young adult flies now mate, sting other bee larvae, lay their eggs, and 
continue the cycle. The time which elapses from the egg of this 
parasitic insect to the adult is given as about from 10 to 12 days. 
This, to his mind, explained the rapid increase of the exciting cause 
of foul brood. As a result of the parasitic existence of this fly in the 
bee larvae, these larvae die and change into a ropy, sticky, ill-smelling 
mass which the bees can not remove. 

Furthermore, he argues that if instead of the diseased larvae dying, 
as they do, after capping, they should die before this stage was 
reached, then the dead bodies would be removed early and with them 
the larvae of the fly; but since the brood is always capped before death 
takes place the capped cells afford a protection for the parasitic 
insect until it becomes an adult ready to emerge. 

In making a diagnosis, it is stated, the cell-cappings should be 
examined, and if they are punctured then the disease is positively 
the infectious foul brood. As a treatment for the infestation of the 
brood by this insect in a colony in which infectious foul brood already 
exists, it is recommended that the combs be removed to a clean hive 
with new foundation, and that the treated colonies and other colonies 
in the apiary be protected by pouring at frequent intervals camphor 
dissolved in oil of turpentine, between the hives in the yard and also 
sometimes on the alighting boards. This is done to prevent, by the 
odor of the turpentine and the camphor, the entrance of the ichneumon 
fly into the hives. 

Preuss, October 1, 1868. 

In a paper written by Preuss, 1 in 1868, his views on the causes of 
foul brood are given. The distinction which he would make between 

1 Preuss, Dr., October 1, 1868. Das Wesen der bosartigen Faulbrut besteht in einem mikroskopischen 
Pilze, Cryptococeus alvearis. Sie kann verhutet und geheilt werden. Eichstadt Bienenzeitung, 24 Jahrg., 
Nro. 19 u. 20, pp. 225-228. 



16 HISTORICAL NOTES ON BEE DISEASES. 

mild and virulent foul brood is, that virulent foul brood is caused 
by a fungus which he named Cryptococcus alvearis, and that the mild 
foul brood is due to some other cause. His conclusion concerning 
the virulent foul brood was reached through a microscopic study of 
foul-brood material. Preuss had been somewhat familiar with bee- 
keeping since early boyhood, and had had the opportunity of visit- 
ing numerous apiaries in the Vistula Valley, but had not encountered 
foul brood until in 1866, when a friend had called his attention to the 
disease in an apiary of the latter in which he was using the Dzierzon 
hives. Preuss immediately undertook the investigation of the char- 
acter of the disease by studying microscopically the larvse which had 
died of the disease. A small bit of the dead larvse was added to a 
little water, covered with a glass, and studied in the fresh condition. 
Numerous spherical bodies measuring 2 \i in diameter were seen and 
identified by him as belonging to the genus Cryptococcus, to which 
he gave the name Cryptococcus alvearis. Larger objects which were 
present were recognized as fat bodies. 

Very nearly related to this organism, Preuss writes, is a fungus 
that causes fermentation, Cryptococcus fermentum. It was his belief 
that if this latter species infected or fell upon a larva it might, under 
favorable temperature and moisture conditions, change into Crypto- 
coccus alvearis and in this way produce foul brood. Practical bee 
keepers had, prior to this time, emphasized the danger of foul brood 
transmission by the feeding of fermented honey. One bee keeper of 
large experience had attributed foul brood to meal feeding, and since 
meal is a good medium for the growth of fungi, Preuss was inclined 
to favor the view. He argued that since the fungus of fermentation 
is widespread in nature, the brood dying from cold or neglect of any 
kind may constitute a fruitful soil in which this fungus could grow 
and thus become the cause of infectious foul brood. Medication in 
the treatment of the disease Preuss held to be quackery and recom- 
mends instead the removal of the diseased frames from the hive, but 
not the destruction of the hives. The hives were to be washed with 
10 per cent sulphuric acid, followed by water, and afterwards put 
into an oven and heated to the boiling temperature for some hours. 
The frames containing diseased material were to be burned, and 
those frames which were free from such material were to be used 
again. All dead bees were to be buried, as they might become a 
source of fungous growth, and the ground in front of the hive was to 
be sprinkled with sulphuric acid and then dug up deeply. 

SCHONFELD, NOVEMBER 15, 1873. 

In the absence of conclusive experimental proof, the theories 
advanced by Preuss in the paper just considered were not univer- 



SCHONFELD, NOVEMBER 15, 1873, 17 

sally accepted. Schonfeld, 1 therefore, set about to supply incontro- 
vertible evidence to prove the cause of infectious foul brood. He 
received a small mass of decaying larvae about the size of a pea and 
placed it under an inverted funnellike apparatus. An opening for 
the admission of air was made from below; the exit was an opening 
above in which was placed a stopper made of cotton. Placing this 
apparatus near the window, that it might receive the heat of the sun, 
he hoped, by the current of air which would thus be produced, to 
collect on the cotton, filling the exit, the spores of the fungus which 
would be floating off in the air from the foul-brood mass. Upon 
examining the cotton he found what he supposed was the fungus in 
the form of a micrococcus. This was the first part of his experiment. 
In the second part of it he used this cotton to infect healthy larvae. 
Four square inches of brood was covered by a layer of cotton. The 
cotton was taken from one of the stoppers that had been contami- 
nated with the fungus by means of the apparatus. After two unsuc- 
cessful trials he made a third attempt, which was considered by him 
as being successful. After a lapse of four days seven larvae had 
died and numerous micrococci were found in their dead bodies. 

In another experiment the same author used the larvae of the blow- 
fly (Musca), CallipJiora vomitoria. Some cotton contaminated in 
the manner outlined in his first experiment was placed upon some 
meat upon which these larvae were feeding. Nine days after adding 
his supposed virus he found dead larvae which upon microscopic 
examination revealed to him again the presence of numerous micro- 
cocci. The results of these experiments convinced him that this 
micrococcus was the cause of infectious foul brood, and he believed 
that the fact -would be accepted without question. 

The experiments of Schonfeld were not, however, universally 
accepted as conclusive. This induced him to perform other infec- 
tion experiments. This time he used caterpillars of (Pieris) Pontic 
brassicse and (Pieris) Pontia rapse. The virus was mixed in dis- 
tilled water and painted on the exterior of the insect, with the result 
that those so treated died while the checks developed normally to 
healthy pupae. Microscopically, however, the check caterpillars 
showed also the presence of the fungus. This caused him to doubt 
somewhat his conclusions relative to the blowfly experiment. He 
believed, however, that sufficient evidence had now been produced 
to justify the conclusion that infectious foul brood is a mycosis and 
that the fungus Cryptococcus alvearis is the exciting cause of the 
disease. 

i Schonfeld, Dr., November 15, 1873. Faulbrut-studien, Pt. I. Eichstadt Bienenzeitung, 29 Jahrg., Nro. 
21, pp. 250-254; January 15, 1874. Faulbrut-studien, Pt. II, Eichstadt Bienenzeitung, 30 Jahrg., Nro. 1, 
pp. 3-5. 

13140°— Bull. 98—12 2 



18 historical notes on bee diseases. 

Dzierzon, 1882. 

For many years Dzierzon and others entertained the belief that 
there existed two forms of foul brood, a mild form and a virulent one. 
In his " Rational Bee Keeping/' Dzierzon 1 has written the following 
concerning the kinds of foul brood. 

There is one kind that is mild and curable, and another kind malignant and incura- 
ble; both kinds are, however, contagious. 

The curable occurs in this way: More of the larvae die still unsealed, while they are 
still curled up at the bottom of the cell, rotting and drying up to a grey crust, that may 
be removed with tolerable ease. The brood which does not die before sealing mostly 
attains to perfection, and it is only exceptionally that individual foul-brood cells are 
met with sealed. 

This is exactly reversed in the malignant kind of foul brood. In this the larvse do 
not generally die before they have raised themselves from the bottom of the cell, have 
been sealed and begun to change into nymphs. The rotten matter is, therefore, not 
found on the cell floor, but on the lower cell wall; it is brownish and tough, and dries 
up to a firm black crust, both in consequence of the heat prevailing in the hive, and 
of a small opening bitten in the depressed cover. This matter the bees are not able 
to remove; and when they are in some strength, they can at most get rid of it by entirely 
biting down the tainted cells and making fresh ones. 

The description which Dzierzon here gives of the "mild" form of 
foul brood applies very well to European foul brood, and his de- 
scription of the " malignant" form applies equally well to American 
foul brood. It is fair to suppose that he encountered both European 
foul brood and American foul brood, but instead of recognizing them 
as two distinct diseases, he thought them to be two forms of the same 

disease. 

Cheshire, August 1, 1884. 

The work of Cheshire on the cause of bee diseases is of much in- 
terest and should be somewhat carefully considered, inasmuch as it 
has directly and indirectly caused much confusion in the minds of 
bee keepers concerning the nature, cause, and treatment of foul 
brood. 

The first paper 2 by him to be considered was the outgrowth of an 
invitation by a committee of the British Bee Keepers' Association 
about the last of May, 1884, to give an address before the association 
on foul brood. A paper of considerable length was prepared and 
was read before that body of bee keepers on July 25, 1884. In this 
address the subject of foul brood was taken up under three separate 
headings: (1) "The nature of foul brood as a germ disease;" (2) 
"The means of the propagation of the disease;" (3) "The method of 

i Dzierzon, Johannes, 1882. Dzierzon 's Rational Bee Keeping; or the theory and practice of Dr. Dzier- 
zon. Translated from the latest German edition by H. Dieck and S. Stutterd. Edited and revised by 
Charles Nash Abbott, London. Pp. xvi+350. 

* Cheshire, Frank R., August 1, 1884. Foul brood (not Micrococcus, but Bacillus), the means of its prop- 
agation and the method of its cure. British Bee Journal, Vol. XII, No. 151, pp. 256-263. 



CHESHIKE, AUGUST 1, 1884. 19 

cure." As Dzierzon and others had done, Cheshire refers to two 
forms of foul brood. Concerning the appearance of these two forms 
of the disease, he writes as follows: 

The appearance of foul brood is undoubtedly familiar to almost all before me. A 
larva, if attacked early, begins to move unnaturally, and instead of lying curled round 
on the base of the cell frequently turns in such a way as to present its dorsal (back) 
surface to the eye of the observer. A little attention will then show that the colour of 
the larva is inclined to yellow instead of being pearly white. Such grubs are only 
rarely sealed over. Those more advanced before the disease strikes them are in due 
course sealed, but death overtakes them, their bodies become brown and foetid, and 
the sealing sinking gets pierced by an irregular hole. From this may be gathered the 
general indications of the disease, which is usually accompanied by very energetic 
fanning at the hive mouth, from which in advanced cases an indescribable and nau- 
seating odour is emitted. The larvae and chrysalids dead of the disease dry up to a 
coffee-coloured, tenacious mass lying at the bottom of the ceil, so tenacious, indeed, 
that it may be drawn out into long threads like half -dry glue. The drying process 
completed, a blackish scale is all that remains. 

Cheshire gives here a description of the disease very similar to the 
one found in Dzierzon's writings. His description of the disease when 
it attacks the larvae early in the developmental stage fits quite well 
that of European foul brood; and the description which is made of 
the brood which is attacked later in the stage of development is 
equally accurate for American foul brood. There is little room for 
doubt that the two forms of foul brood described by Dzierzon and 
Cheshire are the two distinct diseases, European foul brood and 
American foul brood. 

Cheshire began his study of the disease by examining the juices 
of healthy larvae microscopically. In these he found no bacteria. 
He then examined the coffee-colored, foul-broody, dead larval mass 
and observed numerous ovoid bodies which he demonstrated later 
to be the spores of bacteria. This led him to suspect that Schonfeld 
had fallen into the error of supposing that these spores were micro- 
cocci. Having found numerous spores in the remains of larvae which 
had been dead for a long time, he examined some larvae which were 
dead but in a fresher condition. In these he observed many rodlike 
bacteria and fewer spores. He next examined larvae which showed 
signs of disease, but which were yet alive, and found their juices to 
be rilled with actively motile rods. These rods were sometimes ar- 
ranged in chains — leptothrix forms. He now examined larvae rep- 
resenting the different stages of the disease, and observed: First, 
that in the beginning of the attack, rods only were seen; second, 
as the disease advanced, the rods began to form spores; third, as the 
larvae assumed the viscid state, spores were very rapidly formed; 
and fourth, in a few days only spores in very large numbers were 
found. These observations on the morphology of the bacillus are 
good, but the conclusion which he drew from them, "Foul brood, 
then, is a bacillus disease," is of course unwarranted. 



20 HISTORICAL NOTES ON BEE DISEASES. 

Cheshire, believing that foul brood was due to a bacillus and not 
to a micrococcus, as claimed by Schonfeld, sought to demonstrate the 
fact by repeating the inoculation experiments of the latter, using the 
larvae of the blowfly used by Schonfeld (Musca) CallipTiora vomitoria. 
Sixty blowfly larvae were divided into three equal groups: 20 were 
not brought near foul-brood material; 20 were inoculated with the 
bacillus in the vegetative form; and 20 with the spores of the bacillus 
contained in the coffee-colored foul-brood material. Microscopic 
examination at the end of 24 and 48 hours failed to give evidence of 
disease in the fly larvae. After 72 hours, however, active bacilli were 
observed. Cheshire writes, "This is most completely confirmatory 
of my position; but how could it be reconciled with Schonf eld's 
assertion, that he found the dead flies full of micrococci? Had he 
searched further, he would have discovered that dead blowflies are 
generally full of micrococci.' ' In demonstrating this error of Schon- 
feld, he unfortunately made an error quite as great himself. 

Cheshire attempted to obtain, by cultures, proof to support his 
contentions concerning the etiology of foul brood. He prepared a 
medium by taking drone larvae and expressing and straining their 
juices into two test tubes. Tube No. 1 was inoculated with a small 
quantity of coffee-colored material, which for the most part contained 
only spores; tube No. 2 was inoculated with a trace of fluid from a 
diseased larva which contained the vegetative form of the bacillus. 
These tubes were then suspended in a hive between the frames 
in order that the temperature for growth might be right. After a 
period of 22 hours an examination was made. Observing practically 
no spores and many bacilli in tube No. 1, and many bacilli in tube 
No. 2, he reached the conclusion that many of the spores introduced 
into No. 1 had germinated, and that the bacilli introduced into 
No. 2 had increased by multiplication. From this he concludes 
that the rods were produced from the spores when suitable condi- 
tions permitted the germination of the latter, and that the rods pro- 
duced the spores when the reverse conditions were present. From 
the technique used, of course, the data he obtained could be of very 
little value. Thus Cheshire's culture experiments failed as completely 
in demonstrating the etiology of foul brood, as did his experiment 
with blowfly larvae. The experiment, however, is of some interest 
as it is among the first cultural work done on bee diseases, and also 
because here larvae of bees were used as a medium. 

Aside from the larvae, Cheshire suspected that adult bees suffered 
from foul brood. He was of the opinion that if two colonies, a healthy 
and a diseased one are selected for observation, and 5,000 larvae be 
removed from the healthy one, and 1,000 larvae die of disease in the 
diseased one, that the healthy colony will progress pretty much as 
though it had lost nothing, while the diseased one will, as a rule. 



CHESHIRE, AUGUST 15, 1884. 21 

diminish very perceptibly in strength. This difference in the strength 
of two such colonies suggested to Cheshire the probability that the 
adult bees died from foul brood. 

In an attempt to settle this question he went to a foul-brood colony 
and observed one bee dead, another hopping in abortive flight, and 
finally a third and fourth worn out. The microscopic examination 
of the first bee was negative, but the second bee was full of active 
bacilli. This, he believed, was sufficient to answer the question. 
From this he concluded that workers and drones suffer from the 
disease, which suggested to him. the possibility that the queen suffers 
also and, if the queens suffer, he says, why are the eggs not also 
affected? As a result of these observations he suggested that the 
name foul brood is inappropriate, since as he supposed, the disease 
affects adults as well as brood. 

At this point in his paper Cheshire gave to the bacillus which he 
saw the name Bacillus alvei, meaning bacillus of the hive. This name 
he claims represents both generically and specifically what the dis- 
ease really is. 

In the treatment to combat the disease he recommended the feed- 
ing of phenolated sirup, in the proportion of 1 part pure carbolic 
acid (phenol) to 500 parts sirup. This drug had been used, however, 
in the treatment of bee diseases before Cheshire recommended it. 
In expressing his apparent confidence in carbolic acid as a cure for 
foul brood, he writes: 

I could take an apiary beginning of March with every stock diseased, and by May 1, 
with but very little labour, deliver it up clean and strong, as strong as though the 
disease had never appeared. 

Naturally many practical bee keepers who had had experience with 
foul brood hesitated to accept literally such a broad statement. 

Cheshire, August 15, 1884. 

The idea which many bee keepers have that a queen with diseased 
ovaries will transmit the disease to the brood is largely based upon 
the writings of Cheshire. 1 In a paper he relates his observations 
in support of his belief that the queen may be responsible for foul 
brood in a colony. He received from a bee keeper a queen, nearly 
dead, that was taken from a colony in which some of the larvse 
seemed to die immediately after hatching. One ovary from this 
queen, which was yellow and soft, was removed. A portion was 
examined under a microscope, and four or five bacilli were observed. 
Detaching now a half-developed egg, it was placed in a little water 
upon a slide and covered with a cover-glass. Upon examination, 
no less than nine bacilli were seen. The right ovary, it is stated, 

i Cheshire, Frank E,., August 15, 1884. Queen and eggs containing Bacillus alvei— foul brood (?) 
British Bee Journal, Vol. XII, No. 152, pp. 276-277. 



22 HISTORICAL NOTES ON BEE DISEASES. 

was nearly free from disease. After a long search only two or 

three bacilli were found in tins latter ovary. Cheshire now believed, 

apparently, that he had demonstrated the disease in young larvae, 

in older larvae, in pupae, in drones, in workers just gnawing out of 

the cell, in young nurse bees, in old, worn-out bees, and finally in 

the queen and eggs unlaid. Such data as are offered here by Cheshire, 

of course, are insufficient to prove any etiological relation of a bacterium 

to a disease. 

Cheshire, September 1, 1884. 

In an earlier paper (p. 19) Cheshire adhered to the view held 
by Dzierzon and others, that foul brood was of two kinds. 

The view which he expresses in a later article x is that there is 
but one disease and that one is caused by Bacillus alvei. After he 
had examined a number of samples of comb affected with the disease 
he reached the conclusion that Dzierzon was in error in asserting 
that there were two kinds of foul brood, one mild, the other malig- 
nant. While all cases of foul brood, he says, are due to Bacillus alvei 
and to this extent are identical, yet in some cases the spores of this 
organism are larger, more robust, and more virulent than in others. 
When the disease manifests itself early in the development of the 
brood he contends that it is more difficult to cure, if any difference 
exists, than when the symptoms appear later in the disease. He 
contends further that if this disorder is due to the disease lurking 
in the queen she must be removed. 

The doubt that was entertained as to the effectiveness of the car- 
bolized sirup treatment caused Cheshire to perform another experi- 
ment. In a healthy colony he placed, on August 6, six combs secured 
from more than one source, and all affected with foul brood. On the 
following morning he poured medicated sirup into the combs. Similar 
feedings were continued daily in liberal quantities until the sixth 
morning. After this a tin-pan feeder was used, which was not allowed 
to become empty of sirup. Eggs were laid and brood reared in the 
foul-brood combs which had been inserted. Almost all the larvae 
that were reared were healthy. Many of those that were near the 
lower edge of these frames, however, were affected and passed through 
the first stages of the disease. These larvae later disappeared by being 
carried out, it was supposed, by the workers. Only three or four 
sealed cells with diseased brood now remained, and it was believed 
that these would be cleaned out by the bees as soon as the cappings 
were broken. With these exceptions, he says, the hives were, on 
August 23, as perfect as could be desired. Following the description 
of his experiment, Cheshire writes: 

i Cheshire, Frank R., September 1, 1884. The Cheshire treatment of Bacillus alvei (foul brood). British 
Bee Journal, Vol. XII, No. 153, pp. 294-296. 



CHESHIRE, SEPTEMBER 1, 1884. 23 

The Bee Keepers' Record says, in referring to my paper, "Whether phenol is 
really a specific for foul-brood time alone will show, but we urge our readers to give 
it a thorough trial. " I reply that all that could be done to prevent phenol succeeding 
I have done. I have heaped up difficulties: given bees such combs as I venture 
to say they have never received before in the history of bee keeping; secured the 
most virulent type of the disease I could discover, and yet in seventeen days a most 
perfectly healthy aspect is presented, and the bees, with brood in their six frames, 
are hard at work comb-building. I assert, with all the positiveness I can command, 
that phenol, upon my plan, is a specific, and only needs a careful and correct applica- 
tion. 

Bee keepers who have had experience in the treatment of foul 
brood can decide, first, whether such phenomenal results as Cheshire 
has recorded are to be expected, and, second, whether from one 
experiment like this he should have asserted so positively that the 
method is a specific one. 

The method advocated by Cheshire was given a trial, however, 
by many bee keepers, especially in England. To indicate what 
harm might ensue from such immature work, we quote from a few 
who followed his advice. A questioner * gives the following from 
his experience: 

Having used carbolic acid as a prophylactic in the apiary for more than fifteen 
years, I was delighted to learn that Mr. Cheshire, by putting a little amongst syrup 
and pouring it into the brood-cells of a virulently diseased stock, had succeeded 
in effecting a complete cure. To test its power in this way I procured a bottle of 
medicated material prepared under Mr. Cheshire's guarantee, and began to treat a 
stock, thoroughly foul-brooded, according to the method prescribed — on the 30th 
August last. 

Circumstances were all favourable, such as a high temperature, a breeding queen, 
and bees carrying in pollen. No heat was allowed to escape from the stock through 
imperfect covering. But although the treatment has been carried on till now (Oct. 
20th), there is no more abatement of disease than usually takes place when egg-laying 
becomes languid. The population is getting reduced; the cells perforated and 
closed are filled with gluey, putrid matter, and the stench emitted is scarcely less 
offensive than formerly. 

What the treatment can effect in spring and summer, when greater heat and activity 
prevail, remains to be tested; but from what has come under my observation I have 
come to the conclusion that unless the apiarian himself clear out every foul cell, no 
virulently diseased hive can be restored to perfect health in the autumn by administer- 
ing phenol as Mr. Cheshire directs. 

From another bee keeper 2 we quote the following : 

I have used Mr. Cheshire's cure, and followed his directions to the best of my 
ability, but it has proved in my case a complete failure. 

From another 3 the following is quoted : 

During the latter end of July I observed that three of my bar-frame hives were 
affected with foul brood. I was a little puzzled what to do, as I never had had any 

1 Questioner, November 1, 1884. Phenol no cure in autumn. British Bee Journal, Vol. XII, No. 157, 
p. 379. 

2 Johnston, Arthur B., November 1, 1884. Is phenol a cure for foul brood? British Bee Journal, Vol. 
XII, No. 157, p. 379. 

a Veritas, November 15, 1884. Foul brood. British Bee Journal, Vol. XII, No. 158, pp. 399-400. 



24 HISTORICAL NOTES ON BEE DISEASES. 

experience of nor had I seen the disease before. However, from the confident way 
in which Mr. Cheshire spoke of his phenol cure, I resolved to try it, and as honey 
was still coming in, I had to pour the medicated syrup over the brood-combs; but 
as soon as the ingathering of honey ceased, I extracted all the combs in my apiary 
and commenced to feed ; and after a little experience of it, I found that 1 in 600 was 
as much as the bees would take. When enough of this had been deposited and sealed 
for winter stores, I made a thorough examination, and found that it had not cured 
a single one, but the disease had spread to others that were being fed with the carbolised 
syrup. I then withdrew the combs from two of the worst, and gave them empty 
ones to begin in, re-fed them 1 in 600 of Calvert's No. 1; the disease spread again, 
and I lost all faith in the Cheshire cure. 

Cheshike, September 15, 1884. 

Two weeks later another article x by Cheshire appeared, in which 
the origin of the names Bacillus depilis and Bacillus gaytoni is found. 

Many cases had been reported in which numerous small, hairless 
bees had been found in front of the hive. These had been con- 
sidered simply as robbers. It seems, however, that Miss Gay ton, a 
bee keeper and observer, had furnished Mr. Cheshire some of these 
bees, together with her notes for examination. He examined the 
bees and found in them in every case a bacillus smaller than Bacillus 
alvei, and by work done in the Biological Laboratory at South Ken- 
sington they were believed to be entirely distinct species. In his 
paper Cheshire writes: 

This bacillus, undoubtedly, produces this effect [premature baldness] and so again 
I claim the right of giving a name, and so suggest Bacillus depilis, or the bacillus of 
hahiessness, as a fitting one. Although, perhaps, Bacillus gaytoni would be better 
remembered and only a well-deserved compliment. 

Here again it is noted that data are wanting to justify the conclusions 
drawn. 

Cheshire in the same article gives also a few laboratory notes of 
'some interest to support his view that Bacillus alvei is the cause of 
foul brood. He, together with Cheyne, inoculated some gelatin tubes 
with a small quantity of the coffee-colored remains of diseased cells. 
Subcultures to the seventh generation were made. The character of 
the growth thus obtained indicated that the organism was unknown. 
The cultures were described as having the same characteristic odor 
that is encountered in hives containing foul-brood material. This 
he believed to be strong evidence that Bacillus alvei is the cause of 
foul brood. In this same paper he anticipated the proof to be 
obtained from the inoculation of a healthy colony with Bacillus alvei. 
The twelfth generation of the culture was to be mixed with water 
and sprayed over a card of healthy brood. Concerning the results to be 
obtained he writes: "I will not prophesy, although I foresee the 
results." At that stage of his investigation it was unwise, of course, 

1 Cheshire, Frank R., September 15, 1884. Bee diseases in relation to apiculture and general science — 
Bacillus gaytoni (?). British Bee Journal, Vol. XII, No. 154, pp. 317-318. 



CHESHIRE AND CHEYNE, AUGUST, 1885. 25 

to entertain such hopes. It might at first seem to the reader that 
Cheyne was jointly responsible with Cheshire in these statements, 
but it will be learned later that the responsibility is with the latter. 

Cheshire, October 15, 1884. 

In another paper ' which appeared one month later, Cheshire 
considers the possibility of the transmission of foul brood from 
drones at the time of mating. He received from a bee keeper a 
queen that had accompanied a swarm, and after beginning to lay for 
the new colony she ceased after about 6 square inches of comb had 
been filled and never laid again. Upon post-mortem examination 
the ovaries and spermatheca were apparently normal to the naked 
eye. The contents of the spermatheca were examined under the 
microscope and many bacilli were found among the spermatozoa. 
An inflamed condition of the mucous gland and valves was reported 
to be present, and this fact was given as the probable reason why the 
oviposition had been arrested. The theory advanced by Cheshire 
to account for the disease was that the colony had recently cast a 
swarm unobserved, and that the queen which had been sent him for 
examination was a young one and in mating had contracted from 
the drone the condition that was observed microscopically. This 
supposition seemed probable to him, because he had seen what he 
identified as being Bacillus alvei among the spermatozoa of drones 
taken from foul-brood colonies. 

Cheshire cites another case: A queen had been sent to him with 
the information that she was an old one. Upon examination he con- 
cluded, on the contrary, that she was young and badly diseased, since 
among the spermatozoa, as in the first case, many bacilli were ob- 
served. Naturally from such observations Cheshire did not prove 
that the cause of foul brood could be transmitted from drone to queen 
at time of mating. 

Cheshire and Cheyne, August, 1885. 

The paper which was prepared by Cheshire and Cheyne 2 con- 
jointly, as the result of the work mentioned in this quotation, was 
read on March 11, 1885, and was published in August, 1885. It 
appears in two parts. Part I, written by Cheshire, considers the 
pathogenic history of "Bacillus alvei," and Part II deals with the 
history of Bacillus alvei under cultivation, which is the portion 
written by Cheyne. The part written by Cheshire contains a sum- 

1 Cheshire, Frank R., October 15, 1884. A new discovery with regard to bacillus disease. Diseased 
spermatheca. British Bee Journal, Vol. XII, No. 156, pp. 355-356. 

2 Cheshire, Frank R., F. R. M. S., F. L. S., and Cheyne, W. Watson, M. B., F. R. C S., August, 1885. 
The pathogenic history and history under cultivation of a new bacillus (B. alvei), the cause of a disease of 
the hive bee hitherto known as foul brood. Journal of the Royal Microscopical Society, Ser. II, Vol. 
V, Part 2, Plates X'and XI, pp. 581-601. 



26 HISTORICAL NOTES ON BEE DISEASES. 

mary of his work on foul brood which appeared for the most part in 
the papers by him which we have already reviewed. In addition to 
the work contained in his former papers he reports the results of his 
experimental inoculation of healthy larvae with cultures of Bacillus 
alvei. 

On page 24 of this bulletin it will be noted that Cheshire outlined 
briefly the manner in which the inoculations would be made, and 
stated furthermore that he could foresee the results. After obtaining 
the results of his experimental inoculation, he writes as follows : 

It is needful before passing to the second head to anticipate one or two points to 
which Mr. Watson Cheyne will especially refer. After very many cultivations con- 
ducted in series by that gentleman, a small quantity of sterilized milk was inoculated 
from the last tube. It behaved characteristically, as Mr. Cheyne will describe, the 
flask emitting upon the drawing of the plug the unmistakable odour so distinctive of 
the disease in the hive. Some of this milk I diffused through water and sprayed from 
an atomizer over a healthy comb of larvae, part of which was protected by a cardboard 
sheet into which four lozenge shapes had been cut. The larvae protected matured 
in health; those exposed to the spray in many cases were removed by the bees, while 
the rest died, their bodies filled with Bacillus alvei. This last experiment seems to 
complete the chain of evidence in favour of "foul brood " not being accidentally asso- 
ciated with this bacillus, but actually its result. 

If positive results can be obtained by experimental inoculation of 
course such results furnish evidence which is of the greatest value in 
the determination of the cause of the disease. Cheshire's experi- 
ment, however, did not furnish such evidence. It will be noted that 
Cheshire states that some of the larvae died with their bodies rilled 
with Bacillus alvei, and while he does not say positively that the 
larvae died of foul brood, this idea is likely to be inferred by the next 
statement that is made. While these statements by Cheshire are 
made with some degree of conservatism, they evidently have been 
interpreted by many to mean that the disease was produced, and 
this conception has led to a great deal of confusion in the minds of 
bee keepers concerning the cause of foul brood. Cheshire states that 
Cheyne will especially refer to the experimental inoculation of healthy 
brood which he only anticipates in his part of the paper. In con- 
sidering Cheyne's contribution it will be seen in what way he disposes 
of this very important phase of the investigation. 

This completes the consideration of the papers by Cheshire as far 
as we purpose to deal with them at present. Before taking up the 
investigations of Cheyne on Bacillus alvei it may be well to summarize 
Cheshire's papers on foul brood. 

1. Having accepted an invitation from the British Bee Keepers' 
Association to give an address upon foul brood, Cheshire began to 
study the disease about the last of May, 1884, although he mentions 
having examined, microscopically, larvae dead of the disease some 
years before. 



CHESHIRE AND CHEYNE, AUGUST, 1885. 27 

2. He gave the results of the first two months' work before a con- 
ference of this association on July 25 of the same year. 

3. Although he started out with Dzierzon's idea that two forms of 
foul brood are to be encountered in studying the disease in the apiary, 
he does not seem to have suspected, while making his observations, 
that probably two distinct diseases were being called by the one 
name — foul brood. 

4. The observations which he made on the morphology of the 
bacillus found in the diseased and dead larvae were very good. He 
probably saw what we now know as Bacillus larvx, but interpreted 
his findings wrongly. Before Cheshire and after him there were sev- 
eral who probably encountered the same bacillus in their studies, but 
who made the mistake of misinterpreting their results. Inasmuch as 
American foul brood is widely distributed in many countries, and 
Bacillus larvse is always found in the larvae dead of the disease, it 
would have been almost impossible for these men not to have seen 
this microorganism. 

5. Cheshire, by his studies on the morphology of the bacillus, by 
his inoculation experiments on blowfly larvae, and by cultures, at- 
tempted to prove that Schonfeld was in error in his investigations. 
It is true Schonfeld had not proved his theory concerning the etiology 
of foul brood, but Cheshire in his attempt to do so failed to prove 
that Schonfeld was in error. 

6. Cheshire began the study of B. alvei culturally with a medium 
prepared from the larvae of bees. He was unfamiliar, however, with 
the technique used in cultural methods, and for this reason too much 
importance should not be attached to his results. Historically, 
however, it is of interest, since it was probably the first cultural work 
to be done in the study of bee diseases. 

7. Inasmuch as he inoculated healthy brood with cultures, one 
learns that Cheshire recognized the advisability of making animal 
inoculations in determining the cause of disease. Unfortunately 
here, too, the methods he used were deficient, and his interpretation 
of the results obtained misled many as to the cause of foul brood. 

8. Cheshire had suspected from some observations which he had 
made that adult bees suffered from foul brood. Examining micro- 
scopically the content of the intestinal tract of an adult bee taken 
from a foul-brood colony, he found many active bacilli to be present, 
and from this observation he was convinced that adult bees, as well 
as larvae, suffer from the disease. Had he, however, examined a 
healthy bee in the same way, he would probably have seen a similar 
condition. 

9. He gave the name Bacillus alvei to the bacillus with which he 
was working. "Alvei," used to designate the species, is very similar 
to the word u alvearis" which Preuss used (p. 16) to designate the 



28 HISTORICAL NOTES ON BEE DISEASES. 

species of the microorganism, Cryptococcus alvearis, seen by him in 
foul-brood larvae. The two may have been the same germ. 

10. From his own work there is no way of knowing positively with 
what bacillus Cheshire was working, since he made no satisfactory 
description for its identification. Later (pp. 31-33) Cheyne made a 
careful description of Bacillus alvei, and Cheshire agreed that it was 
the organism to which he had given this name. 

11. Cheshire asserted positively that his phenol treatment is a 
most effective one for foul brood. Many bee keepers have tried it, 
however, without success. 

12. He concluded upon further study that the two forms of the 
disease described by Dzierzon are one disease, and that this disease 
is amenable to the "Cheshire treatment/' even when the disease 
appears in the most malignant form. 

13. Concerning the difference noticed in samples examined micro- 
scopically, he writes that the more robust spores are associated with 
the more virulent disease. 

14. He was led to believe that the "premature baldness" of 
"black robbers" was due to a bacillus which he saw and named 
Bacillus depilis or Bacillus gaytoni. 

15. He reported that the odor of a gelatin culture of what he sup- 
posed was Bacillus alvei was very similar to the odor observed in 
colonies affected with foul brood. Even if Bacillus alvei were the 
cause of a disease of the brood, one should not expect, of course, this 
similarity. 

16. He suggests the possibility that a queen at the time of mating 
might become infected with Bacillus alvei from a drone reared in a 
foul-brood colony. He expressed a strong conviction that in this 
way foul brood might be transmitted to a healthy colony. 

17. He would have his readers believe that he had found the dis- 
ease in young larvae, in those fully fed, in ch^salids of all stages, in 
drones, in workers just gnawing out of the cell, in young nurse bees, 
in old worn-out bees, and in the queen and the unlaid eggs. 

18. All of Cheshire's papers which have been considered — and we 
have not referred to them all — were prepared in less than one year 
and most of his observations were made in less than half that time. 

We have reviewed these papers by Cheshire in order to point out 
the origin of some of the errors that have crept into bee literature. 
That the several suggestions made by Cheshire were never demon- 
strated to be true will at once be apparent to the reader. The fol- 
lowing criticism offered by Cheshire x on the work of Schonf eld may 
now be applied, it seems, with equal propriety to his own: 

I cannot refrain from expressing my conviction that it is much to be regretted that 
so misleading an account of experiments, to all appearances conclusive and complete, 

1 Cheshire, Frank E,., August 1, 1884. Foul brood (not Micrococcus, but Bacillus), the means of its 
propagation and the methods of its cure. British Bee Journal, Vol. XII, No. 151, pp. 256-263, 



CHEYNE, AUGUST, 1885. 29 

should have been given to the apicultural world. In their absence, it is hardly pos- 
sible that we could have all been in the dark so long. 

Because of the important bearing which the work of Cheshire and 
Cheyne has upon the names of the two infectious bee diseases, and 
upon the names now applied to the bacteria found in the diseased 
larvse, it might be well before taking up the work of Cheyne to con- 
sider these two men briefly and judge from the evidence at hand their 
relation to each other. 

Cheshire was a man who wrote considerably upon bees and bee 
keeping, being apparently more or less familiar with the habits, 
anatomy, and manipulation of bees. From his writings about the 
diseases of bees, however, one at once suspects that his experience in 
this line of apiculture was quite limited. His conception of the 
etiology of diseases in general was evidently very inaccurate. His 
bacteriological knowledge was wanting. l Of this he was undoubtedly 
aware, as he later intrusted this part of the work to Cheyne, who was 
then working in a biological laboratory at South Kensington, London. 

Cheyne is a man who is familiar with the technique of disease inves- 
tigation. He was apparently, however, not familiar with the disease, 
foul brood, at the time he received the sample from Cheshire. This 
fact, however, does not discredit the actual work which Cheyne did. 

If this was the relation existing at that time between these two men, 
and if this is a correct interpretation of their knowledge, respectively, 
of foul brood, then it is not strange that Cheyne should have been 
slightly misled by the opinion of Cheshire on two very important 
points in his work. These two erroneous ideas which Cheyne evi- 
dently gleaned from Cheshire were, firstly, that foul brood was one 
disease, and secondly, that the disease had been produced by Cheshire 
experimentally by using pure cultures of Bacillus alvei. 

Cheyne, August, 1885. 

Cheyne in his contribution * records the first creditable work done on 
the microorganisms found in foul brood. One observes that Cheshire 
writes : 2 

To-day [August 11, 1884] I have been with Mr. Watson Cheyne in the Biological 
Laboratory, South Kensington, and there we have started some experiments, of which 
more will have to be said hereafter * * *. 

And Cheyne begins his paper by writing: 

On August 11, 1884, Mr. Cheshire brought to me a piece of comb containing larvae 
affected with foul brood * * *. 

i Cheshire, Frank R., F. R. M. S., F. L. S., and W. Watson Cheyne, M. B., F. R. C S., August, 1885. 
The pathogenic history and history under cultivation of a new bacillus (B. alvei), the cause of a disease 
of the hive bee hitherto known as foul brood. Journal of the Royal Microscopical Society, Ser. II, Vol. V, 
Part 2, Plates X and XI, pp. 581-601. (For the portion written by Cheyne see also Report of the meet- 
ing of inspectors of apiaries, San Antonio, Tex., November 12, 1906. U. S, Department of Agriculture, 
Bureau of Entomology, Bulletin No. 70, June 17, 1907, pp. 28-35.) 

2 Cheshire, Frank R., August 15, 1884. I. c. 



30 



HISTORICAL NOTES ON BEE DISEASES. 



The sample of comb which Cheshire gave to Cheyne for examination 
then was considered by Cheshire to be foul brood, and therefore was 
thought by the latter to be a sample of the only form of the disease 
that exists under this name. Further Cheyne writes, ' ' selecting cells 
which were closed, but which Mr. Cheshire thought contained dis- 
eased larvae, * * *.» This statement indicates that Cheyne 
was unfamiliar with the gross appearance of the disease as it is found 
m the combs. After uncapping the cells containing foul-brood larvae 
he further writes, " these larvae were dead, of a yellowish colour' 
and almost liquid, * * *.» Capped cells occur more often ii^ 
American foul brood, but are not rare in European foul brood. The 
yellowish color and the almost liquid condition are symptoms which 
would rather strongly suggest that the sample which he examined was 
European foul brood. Numerous rods were found microscopicaUy in 
the diseased larvae. Cultures were made in gelatin and in agar. The 
bacteria found in the larvae and those which appeared in the cultures 
by comparison seemed to be the same. The morphology and cultural 
characters of this bacillus (Bacillus alvei) were carefully studied. 

Concerning the method by which multiplication takes place, Cheyne 
writes : 

The bacilli appear to grow mainly by fission, but I have seen appearances which 
seem to me only explicable on the supposition that they also grow by sending out buds 
from one end. 

A study of the germination of the spores was made, using the 
hanging-drop preparation. A drop of bouillon was placed on a cover- 
glass, inoculated with the spores of Bacillus alvei, and inverted over a 
cell in a glass slide. Preparations made in this manner were placed 
at a temperature favorable for the growth of the bacteria, and from 
time to time studies were made of them by the aid of the microscope. 
He writes: 

In three hours the first indication of sprouting of these spores becomes evident 
The stained part of the spore loses its oval shape, becomes elongated, and is soon seen 
to burst through the spore-capsule at one part. 

From this it is not possible to know whether he observed the capsule 
to burst on the side or at the pole, but the figure to which he refers 
shows the rod bursting through the capsule at or near the pole. 

Having studied the germination of the spores, he proceeded to 
study the formation of the spores in the rod. In doing this two 
methods were employed. The first was by use of the hanging drop, 
similar to that used in his study of the germination. By this method 
he observed in one preparation that most of the rods were beginning 
to form spores in 23 hours, while in another preparation where more 
bouillon was used no evidence of spore formation was present during 



DESCRIPTION OF BACILLUS ALVEI. 31 

the first 28 hours. This led him to conclude that the time when 
spores are produced might depend upon the amount of bouillon used 
and the number of bacilli present. This caused him to devise a sec- 
ond method. The second method involved the use of a flask of sterile 
bouillon, which was inoculated with the vegetative form only of the 
bacillus. This flask was placed in the incubator for two or three 
hours that the organisms might diffuse equally throughout. The 
flask was then shaken, and by means of a syringe gauged on the 
piston equal quantities of the medium and bacilli were taken. In a 
series of preparations thus obtained and kept at 36° C. the earliest 
appearance of spore formation was evident in 41 hours. 

Cheyne records the fact that the swelling in the rod which takes 
place is usually near the center, but sometimes nearer an end. This 
swelling increases in size at its center and gradually fails to take the 
stain. The capsule of the spore, he states, is apparently formed 
within the rod and is not the outer part of the rod. In three or four 
hours after the spore was formed it was either entirely free from the 
rod, or the rod still inclosed the spore, but was almost invisible. 

Having thus studied somewhat carefully the morphology (size, 
form, and structure) of Bacillus alvei, Cheyne took up the further 
study of the species to determine its cultural characters, stating at 
this point, very properly, that the microscope is of little use in deter- 
mining the relation of the bacillus to foul brood. The technique 
which he used in making cultures is very similar to that used in gen- 
eral bacteriological work at the present time, the chief difference 
being that now additional differential media are used. 

DESCRIPTION OF BACILLUS ALVEI. 

The following is an abridged description of Bacillus alvei as given 
by Cheyne: 

Occurrence. — Isolated from larvae said by Cheshire to be affected 
with foul brood. As far as is at present known it has not been found 
elsewhere. 

Gelatin plates. — Gelatin plates were inoculated by stroking the 
solidified medium with the needle. From small masses of growth, 
which soon form along this line of inoculation, bacilli in Indian file, 
or two or three side by side, grow out into the gelatin. These out- 
growths are not straight, but tend to curve, and at a short distance 
from the track of the needle they grow round so as to form a circle. 
From such a circle other fresh circles may be formed. The growth 
about this line increases, rilling up the center of the circle. These 
circular growths increase and may join one another, forming a curved 
anastomosis. The gelatin in the immediate vicinity of the growth 



32 HISTORICAL NOTES ON BEE DISEASES. 

liquefies, and in these liquid channels the bacilli swim to and fro. 
Later some of these channels are apparently deserted of bacilli, so 
that the circles may look as though they were detached from the main 
track. Under low powers, however, the connection between them 
can be traced. 

If the gelatin is inoculated before pouring the plate, the growth 
which takes place is also very characteristic. At first the colonies 
are small and oval or round. Under a low power of the microscope 
the colony does not appear homogeneous, but lines indicating the 
bacilli are seen. The colony soon becomes pear-shaped, and proc- 
esses grow out from the sharp end of the pear into the gelatin. 

Morphology: Rods. — In the larval juices they are rounded or 
slightly tapering at the ends, and often have a clear space near one 
end. Their average length is about 3£ p.. On agar the rods are 
always somewhat pointed at the ends and varying in size. The 
average length is about 3-| p. and the breadth about -§- p. At the 
beginning of spore formation the rods begin to swell and become 
spindle shaped. This increase in diameter is generally near the mid- 
dle, but sometimes it is seen near one end. The capsule of the spore 
is apparently formed within the rod, and is not merely the outer por- 
tion of it. Spores. — The spores are oval, averaging nearly 2pm 
length and nearly 1 p in breadth. Spores from agar cultures are 
generally arranged side by side in long rows. 

Motility. — The bacilli swim with a free oscillating movement. 

Bouillon. — Growth takes place readily, causing a cloudiness of the 
medium and the formation after a few da}^s of a slight but not tena- 
cious pellicle. The odor is similar to that described under gelatin. 
This character is more marked when considerable peptone is present. 
Probably there is no change in the chemical reaction. 

Agar. — The growth is not nearly so characteristic as in gelatin. 
It takes place most rapidly on the surface, forming a whitish layer. 
Here the bacilli arrange themselves side by side and, forming spores 
in this position, there are after a few days, as a consequence, long 
rows of spores lying side by side. 

Blood serum. — Growth takes place slowly, forming long filaments 
and comparatively few spores. 

Potato. — At the incubator temperature the growth takes place 
slowly, forming a dryish yellow layer on the surface. It is very slow 
at lower temperatures. 

Milk. — Growth takes place readily and coagulation occurs. The 
medium assumes a yellowish color and gives off the odor present in 
gelatin-tube cultures. The coagulation is not firm, but like tremu- 
lous jelly and may remain so for a considerable time before the sep- 



DESCRIPTION OF BACILLUS ALVEI. 33 

aration of any fluid takes place. Ultimately, however, it becomes 
liquid, and after some months it assumes the appearance of a dirty 
brownish yellow, glassy fluid. It is very slightly, if at all, acid. 

Gelatin tube. — In this medium the growth is seen on the surface 
and along the line of inoculation. On the surface a ramifying 
growth takes place from the point of entrance of the needle; and 
along the line of inoculation whitish, irregularly shaped masses appear, 
which increase slowly in size. In a few days processes, which are 
thickened at various points and clubbed at the ends, shoot out from 
these masses. The ends of these processes do not seem to unite. 
A beautiful appearance is obtained when only a few bacteria are 
introduced along the line of inoculation. In a few days small round 
colonies become visible to the naked eye. These increase in size, 
and at about the tenth day shoots begin to appear, which radiate in 
all directions from the central mass and become clubbed. As the 
culture becomes older the radiating branches disappear, and only 
small whitish collections of bacilli are seen at various points. Under 
slight magnification, however, tracks of liquefied gelatin are seen 
extending from the central mass to the whitish collections. The 
evaporation which takes place at the top gives rise to the appearance 
of an air bubble. 

Beginning at the top the liquefaction of the gelatin advances 
slowly downward until ultimately the entire tube is liquefied. After 
two or three weeks there is a layer of liquid at the upper part, with 
the growth as before described in the lower part. At first the lique- 
fied gelatin is clear excepting a loose, white, flocculent sediment 
which is present. There may be a thin surface pellicle. Later the 
liquid becomes yellow, and gives off an odor similar to stale but not 
ammoniacal urine. This, Cheyne says, may better be described as a 
"shrimpy" smell. "The yellowish color and the peculiar odor," 
Cheyne writes, "has been found by Cheshire to be distinctive of 
diseased larvas." 

Cheyne made also a few observations with animals inoculated with 
Bacillus alvei. A bluebottle fly which had eaten some of a milk cul- 
ture of Bacillus alvei was placed under a funnel; the next day it was 
found dead, and upon examination its juices were reported to be 
full of the bacilli. Cockroaches were placed in a box with cultures, 
but none of them died. A rabbit, some mice, and some guinea pigs 
received cultures of Bacillus alvei subcutaneously, but in general only 
negative results were obtained. 

A conclusion which Cheyne drew indicates that at that time he 
was pretty thoroughly convinced that Bacillus alvei was the cause 
of foul brood. The belief which he entertained was based upon his 

13140°— Bull. 98—12 3 



34 HISTORICAL NOTES ON BEE DISEASES. 

study of Bacillus alvei, together with the experiment by Cheshire in 
which healthy brood was inoculated with a spray containing a cul- 
ture of Bacillus alvei. In drawing the conclusion Cheyne evidently 
supposed that Cheshire had produced the disease experimentally. 
Had Cheyne known, on the other hand, that this had not been done 
by Cheshire, his conclusion would have been undoubtedly differently 
expressed. 

The description which Cheyne made of Bacillus alvei is very good. 
It contains, however, a number of statements with which he, himself, 
no doubt at the present time would disagree. Such might be expected 
since it has now been 26 years since he did the work. 

There is much data in Cheyne's paper of interest and value. The 
following is a brief summary of his work: 

1. He received a sample of diseased brood from Cheshire on August 
11, 1884, and the paper which contained the results of his work was 
read on March 11, 1885. 

2. He described carefully and accurately the morphology and cul- 
tural characteristics of Bacillus alvei. His description of the organism 
is the first one by which the identification of the species was made 
possible. 

3. The larvae which he examined were yellowish and almost liquid. 
This suggests European foul brood. 

4. He found Bacillus alvei in large numbers in all the larvae exam- 
ined. This, too, suggests European foul brood. 

5. He does not mention either the presence of ropy coffee-colored 
larvae or scales in the sample examined. This suggests that he was 
not studying American foul brood. 

6. He evidently did not encounter Bacillus larvae, since he does not 
mention the presence of any bacteria in the larvae which would not 
grow on artificial media. This, too, is very strong evidence that he 
was not studying American foul brood. 

7. He was misled by Cheshire's inoculation experiment with bees, 
causing a statement to be made in his conclusion which was less 
conservatively expressed than it would otherwise have been. 

While Cheshire and Cheyne did not prove the cause of any disease 
of bees, their work is of importance in determining to what species of 
bacteria the name Bacillus alvei belongs, and also in determining the 
names for the different brood diseases. The microorganism which 
Cheyne so well described has the right to the name Bacillus alvei, 
because the species was first described by Cheyne and his work had 
the sanction of Cheshire, who first used the name. 

It is quite certain that Cheyne was working with the disease now 
known as European foul brood when he secured the data for his 



McLAIN, 1887. • 35 

paper, because his description of the larvae dead of the disease in the 
sample which Cheshire gave to him as foul brood was quite good for 
European foul brood and not good for American foul brood ; because 
Bacillus alvei was found in sufficiently large numbers to lead these 
men to suspect that the organism was the cause of the disorder; and 
because no other species was mentioned as being present in numbers 
sufficient to cause suspicion of a casual relation. All must agree that 
if Cheyne did not work with a sample of European foul brood in the 
preparation of his paper, his work can not be given the credit which 
it seems to deserve. 

McLain, 1887. 

A paper by N. W. McLain, 1 containing a discussion of bee diseases, 
was written in the form of a report on some work done by him. The 
first disorder which he considers is referred to as the u quaking 
disease." It was thought by McLain that bees would visit milkweed 
and mullein to obtain from the sap of these plants certain salts as 
food, if such salts could not be obtained from the ordinary sources. 
In so doing, thousands of bees lost their lives before, as well as after, 
reaching the hives. By examining such bees under a microscope, 
many were found to be entangled in filaments derived from the sap 
of the plants visited, and with empty stomachs. The peculiar nerv- 
ous motions made by these starved and weakened bees in their effort 
to disentangle themselves from the meshes of the fibers is one mani- 
festation of the condition known as the "quaking disease." Another 
form of this disease was supposed to be of hereditary origin, since it 
was believed that by removing the queen from an affected colony and 
introducing a young, vigorous one the trouble would disappear. A 
third form of the disease mentioned had been reported to be due to 
the use of poisonous nectar from such plants as foxglove (Digitalis). 

McLain therefore placed at least three distinct abnormal condi- 
tions under the name " quaking disease." He writes definitely con- 
cerning the cause of the first condition only. The second condition is 
probably that which is now known as paralysis, and the third condition, 
that of poisoning, is occasionally reported by bee keepers as a cause 
of trouble in the apiary. Very little is definitely known at present 
concerning any of these disorders. In the treatment of the first 
condition mentioned he used a drug and reported success. 

McLain also made a report on foul brood. Having spoken of the 
gravity of the disease he writes that he had during the year given 
much attention to the study of the disease and to experiments for its 
prevention and cure. That the disease was contagious appeared to 

1 McLain, N.W., 1887. Report on experiments in apiculture. Report of the Commissioner of Agriculture 
for 1886, pp. 583-591. Washington: Government Printing Office. 



36 HISTORICAL NOTES ON BEE DISEASES. 

him to be certain. The origin and the means of its transmission, 
however, were not entirely clear. That the germs of the disease 
may be carried from apiary to apiary upon the clothing of the apiarist 
and in or upon the bodies of bees, that in the same apiary these 
germs may be borne by the winds from one hive to another, and that 
they may be liberated from the decomposing bodies of other insects 
and scattered to objects with which the bees come in contact, seemed 
to McLain to be probable. It appeared to him. that foul brood 
attacked adult bees as well as brood, that live pollen is the medium 
by which the contagion is most commonly and most rapidly spread, 
and that the disease yields readily to a drug treatment. 

In discussing the idea that the clothing and hands of an individual 
going from one apiary to another might probably be a means by 
which disease germs are transmitted, he writes : 

That the disease germs may be carried upon the clothing and hands appears probable, 
from the fact that in one neighborhood the disease appeared in only two apiaries, the 
owners of which had spent some time working among diseased colonies at some distance 
from home, while other apiarists in that locality who had kept away from the con- 
tagion had no trouble from foul brood. 

In support of his supposition that the wind might be considered 
as a medium by which the germs of the disease may be carried, he 
writes : 

That the contagion may sometimes be borne from hive to hive by the wind appears 
to be true, as it was observed in one of the apiaries which I treated for this disease 
during the past summer that of a large number of diseased colonies in the apiary, with 
the exception of two colonies, all were located to the northeast of the colony in which 
the disease first appeared. The prevailing wind had been from the southwest. 

The report covers the work done by McLain in one year on bee 
diseases. He was conducting at the same time some experiments 
relative to the control of the mating of the queen. Most of his con- 
clusions concerning diseases were drawn, apparently, from three 
experiments performed by an apiarist who reported his results to 
McLain. 

The following is a summary of his report pertaining to bee diseases: 

1 . He made no pretense at a study of bee diseases bacteriologically. 

2. He included at least three distinct conditions in the disease of 
adult bees which he referred to as " quaking disease." 

3. He probably included in the " quaking disease" the disorder 
which is now known to many bee keepers as " paralysis." 

4. He recognized the virulence, wide distribution, and, conse- 
quently, the destructiveness of foul brood. 

5. He probably was not aware that at least two infectious diseases 
of bees were being referred to as foul brood. 

6. Since American foul brood has been the prevailing disease in 
the region in which his experiments were made, and since the descrip- 



McLAiN, 1888. 37 

tion which McLain gives of the appearance of the dead larvae is that 
of American foul brood, he very probably was working with this 
disease. 

7. He seemed to accept the belief that adult bees are affected with 
foul brood as well as the brood. 

8. He supposed that pollen is the medium by which the infection 
is usually transmitted. 

9. He evidently believed in the efficiency of the drug treatment of 
bee diseases. 

Let us now consider for a moment some of his contentions. One 
must agree with McLain that the diseased condition then known as 
foul brood is an exceedingly serious one, causing great loss to the bee 
keepers. That the disease is quite infectious has often been demon- 
strated. That the germs of the disease may be carried from one 
hive to another in and upon the bodies of the bees seems very prob- 
able. That the germs are carried from one colony to another upon 
the clothing of the bee keepers and that the infection is transmitted 
in tins way is extremely improbable. That the germs are carried by 
the winds from one hive to another in the apiary is likewise very 
improbable. That the germs of the disease are liberated from other 
insects and afterwards taken up by bees is not probable. 

In many ways this report by McLain is a conservative one. Suf- 
ficient evidence was wanting to prove most of the points in his paper. 
He probably realized this fact, and for this reason, as a rule, he did 
not make positive statements. Inasmuch as his report covers the 
work of a single season, very little definite information could be 

expected. 

McLain, 1888. 

In his report * on the succeeding year's work McLain discusses some- 
what again the question of bee diseases. This report shows the 
influence of Cheshire's writings, since McLain now speaks of the 
inappropriateness of the name foul brood (p. 21) and the certainty 
of the etiological relation between Bacillus alvei and the disease (p. 20). 
Furthermore he refers to the statements of Cheshire concerning the 
probable spread of disease through the air and by means of the clothes 
and hands of the operator, and says that Cheshire's observations are 
in agreement with his own which he included in the preceding report. 

McLain had expressed (p. 36) his firm belief in the theory that 
pollen was the common source of infection in foul brood, and not 
honey, as was commonly supposed. This view, he thought, was 
strengthened by some statements which Cheshire made. McLain 
was of the opinion that undue importance was being attached to 
honey as a medium through which the infection is transmitted, and 

i McLain, N. W., 1888. Report on experiments in apicnlture. Report of tne Commissioner of Agriculture 
for 1887, pp. 170-178. Washington: Government Printing Office. 



38 HISTORICAL NOTES ON BEE DISEASES. 

expressed his convictions that there was but little doubt that pollen 
is the medium by which the contagion is most commonly introduced, 
most rapidly spread, and most persistently perpetuated. 

McLain also includes in his report some remarks on starved brood, 
and in referring to the symptoms states that in this condition the 
brood is frequently found to be only partially capped, giving the 
appearance commonly designated by the term "baldheaded brood." 

In estimating the value of this work by McLain, it must be borne 
in mind that McLain had evidently a very indefinite conception of 
the phenomena which are encountered and must be dealt with in the 
study of disease; that he devoted but little time to the study of the 
disease he referred to as foul brood, and that he was probably unduly 
influenced by the writings of Cheshire. For these reasons it is 
advised that his reports be not taken too seriously. 

Lortet, February, 1890. 

A paper * by Dr. Lortet concerning some of the bacteria encoun- 
tered in the study of foul brood appeared in 1890. He found two 
species always present in the digestive tract of healthy adult bees as 
well as in those diseased. These species were reported to be present 
also in the digestive tract of both healthy and diseased brood. The 
fact was pointed out that these bacteria had probably led some authors 
into error in their work. The two species were not named nor suf- 
ficiently described to make their identification possible. He en- 
countered also, in the digestive tube of brood diseased and dead of 
foul brood, another species which he supposed was Bacillus alvei and 
which was the cause of the rapid death of the larva?. Lortet records 
no difficulty in cultivating this species on the ordinary media. 

It was his belief that adult bees suffered from the disease, but that 
they resisted the infection more than the larvae, and finally died as a 
result of the infection. Experimentally, he claims to have obtained 
positive results in support of his views. He examined one queen 
taken from an infected colony and from a study of her he reported 
that she was perfectly healthy and that her eggs were free from 
bacteria. It was his opinion that food was the source of infection of 
the digestive tube of the nurse bees and that the nurse bees became in 
turn the source of infection for the brood. 

From his work he drew the following three conclusions: (1) That 
Cheshire had found the true exciting cause of foul brood and declared 
that the fact had been verified by numerous laboratory experiments ; 

(2) that it is useless to attempt to save larvae already infected, and 

(3) that adult bees which become infected may live a long time, and 
some may even resist the attack completely. 

1 Lortet, Dr., February, 1890. La bacterie loqueuse. Traitement de la loque par le napbtol /3. Revue 
Internationale d 'Apiculture, Tome XII, No. 2, pp. 50-54. 



MACKENZIE, DECEMBER, 1892. 39 

Believing that the digestive tract of the adult bee was the source 
of infection for the larvae, he recommended, as the most rational 
treatment, the use of an intestinal antiseptic in the form of sirup 
medicated with beta naphthol, a drug which had been used for some 
time as an intestinal antiseptic in the practice of human medicine. 
The feeding of sirup medicated with beta naphthol (one-third gram 
beta naphthol to 1,000 grams of sirup), he reports, was sufficient in his 
experiment to free the intestinal tube of the bacteria causing the 
trouble. This cure he supposed took place rapidly and completely 
except when the bacteria had reached more completely the different 
portions of the alimentary tract. 

One observes that the views entertained by Lortet on bee diseases 
are quite different from those entertained at the present day con- 
cerning these disorders. 

Mackenzie, December, 1892. 

In 1892 Mackenzie read a paper x on Bacillus alvei which he had 
prepared at the request of the Bee Keepers' Union of Canada. The 
relation which was supposed by Mackenzie to exist between foul 
brood and Bacillus alvei is shown in the following brief review of his 
paper: 

He received from a bee keeper some samples of diseased brood for 
examination. He began the study of these samples upon the assump- 
tion that Cheshire and Cheyne had already found Bacillus alvei and 
by inoculation with pure cultures had demonstrated this organism to 
be the cause of the disorder. By finding an organism which he 
thought from its morphology and cultural characters was Bacillus 
alvei, the conclusion was reached that the samples were foul brood, 
the same as was found in other places. 

Laboring under the erroneous conception that Bacillus alvei is the 
cause of the foul brood prevalent in Ontario, Mackenzie proceeded 
with the study of the bacillus identified by him as Bacillus alvei. 
The first task mentioned in his paper which was undertaken by him 
was the solution of the question whether in the making of wax foun- 
dation sufficient heat is applied to destroy the vitality of the foul- 
brood spores. After receiving replies from different foundation manu- 
facturers concerning the highest temperature reached in the process 
and the time the wax was kept at this temperature, and after mak- 
ing some determinations of the thermal death point of the spores of 
the bacillus, he writes: "I am inclined to think there is little danger 
from foul brood in that direction." He found by a cultural method 

i Mackenzie, J. J., B. A., December, 1892. The foul brood bacillus (B. alvei); its vitality and develop- 
ment. Eighteenth Annual Report of the Ontario Agricultural College and Experimental Farm, pp. 
267-273. 

This address is quoted in full in the Report of the Meeting of Inspectors of Apiaries, San Antonio, Tex., 
Nov. 12, 1906. (Bulletin No. 70, Bureau of Entomology, U. S. Department of Agriculture, 1907, pp. 36-42.) 



40 HISTORICAL NOTES ON BEE DISEASES. 

that 2 per cent carbolic acid would not kill the spores of Bacillus alvei 
in six hours, and concluded that carbolic acid in this strength could 
not be relied upon as a hive disinfectant to destroy the spores of 
tins organism. 

Mackenzie says that if the shaking treatment is employed, the 
question of the presence of Bacillus alvei in the workers, queen, and 
eggs must be considered in the discussion of the value of such treat- 
ment. He claims to have confirmed the results obtained by Cheshire 
that the bacilli are sometimes found in the intestine of the worker 
and the ovaries of the queen, but that the finding of the bacillus in 
the eggs of an infected queen needs confirmation. 

He reports an experiment from which he concluded that carbolic 
acid (1-500), as used in medicated sirup in the treatment of foul 
brood, does not kill the spores but prevents their germination, and 
thus gives the bees a chance to rid themselves of the infection. "Its 
advantage," he writes, in comparing it with a shaking method, "is 
that it can be carried on for a longer time. " Concerning beta naph- 
thol, he concludes that a 1-1,000 solution in bouillon possesses the 
same value as an antiseptic as a 1-500 solution of carbolic acid 
and he believed that it would probably be more acceptable to the 
bees. The use of salicylic acid was thought by him to be followed 
by about the same results as carbolic acid and beta naphthol in the 
medication of sirup. For the cleaning of hives and frames he recom- 
mends a 10 per cent solution of soft soap or washing powder. 

The following points of interest are found in Mackenzie's paper: 

1. He accepted the work of Cheshire and Cheyne as demonstrat- 
ing conclusively that Bacillus alvei is the cause of foul brood, and 
used in his laboratory experiments a bacillus which he identified as 
this organism. 

2. At the time Mackenzie's paper was written his work on foul 
brood had been carried on for only about a year, and he appreciated 
the fact that his work was by no means complete. 

3. From the report of foundation manufacturers and from the 
results of his own investigations, he was inclined to believe that 
there is but little danger of infection from foundation made from 
wax taken from a foul-brood colony. 

4. He isolated Bacillus alvei from the ovaries of three of the five 
queens examined, but believed that the findings of Cheshire with 
respect to the eggs need confirmation. 

5. He interpreted the finding of Bacillus alvei in the intestines of 
workers and queen as a fact worthy of consideration in the shaking 
treatment. 

6. He believed that drugs in the treatment of foul brood have a 
value in preventing the germination of the spores. 



HOWARD, MARCH 1, 1894. 41 

The greatest mistake made by Mackenzie in his work was of course 
that he assumed that Bacillus alvei had been demonstrated to be the 
cause of foul brood. 

The work which Mackenzie began was to have been continued the 
following summer, but, in a report 1 of the Apicultural Committee 
of the Ontario Agricultural and Experimental Union one notes that 
Mackenzie, who had the preceding year given his services in connec- 
tion with foul brood, for the want of time had not continued his 
studies. 

Howard, March 1, 1894. 

In 1894 there appeared from the pen of William R. Howard, 2 of 
Fort Worth, Tex., a small publication on foul brood. He makes 
clear in his preface that there is yet much to be learned upon the sub- 
ject, and that his communication is to be written in such a manner, 
and such terms are to be used in it, as will be readily understood by 
the general reader. 

In his brief reference to the history of foul brood, Howard writes: 

Later the researches of Preuss and Schonfeld, of Germany, were first to establish the 
fact that the disease was due to pathogenic micro-organisms. 

Howard, therefore, in the beginning entertained an erroneous 
conception concerning the real work accomplished by Preuss (p. 15) 
and Schonfeld (p. 16). 

The description given of Bacillus alvei was taken, as he says, from 
" Eisenburg's Bacteriological Diagnosis. " The description of Bacillus 
alvei by Eisenburg was compiled from the joint publication by Chesh- 
ire and Cheyne (p. 25). Howard made some determinations con- 
cerning the ability of the species to produce gas and the ease with 
which it grows in the presence or absence of oxygen. He reports 
that the cultures, when grown under anaerobic condition, produce 
an odor resembling foul brood. Eisenburg does not include in his 
description any mention as to the oxygen requirements of Bacillus 
alvei. The only difference, it seems, between the description which 
Cheshire and Cheyne made of Bacillus alvei and the conception which 
Howard had of it, is in the fact that Howard thought that it grows 
better under anaerobic conditions, while Cheshire and Cheyne ob- 
tained very satisfactory growth on the surface of media exposed to 
the air. 

Propositions are stated by Howard in his paper, and his own inter- 
pretations of them are given. Some of his views can be accepted 
as good, others can not. 

1 Holtermann, R. P., Monteith, S. N., Husband, E. M., 1893. Report of Apicultural Committee. 
Fifteenth Annual Report of the Ontario Agricultural and Experimental Union. Pp. 230-231. Contained 
In Nineteenth Annual Report of the Ontario Agricultural College and Experimental Farm. 

2 Howard, Wm. R., M.D., March 1, 1894. Foul brood; its natural history and rational treatment, with 
a review of the work of others. Chicago, HI. Pp.47. 



42 HISTORICAL NOTES ON BEE DISEASES. 

His reference to the gross appearance of the disease material with 
which he was working strongly suggests that the disorder was Amer- 
ican foul brood. In every case that he examined he reports the 
presence of Bacillus alvei. 

Howard, September 10, 1896. 

Having gotten Howard's conception of foul brood and Bacillus 
alvei, we shall pass to another paper * by the same writer. 

The term " pickled brood/' which is often used by bee keepers, 
had its origin apparently in an article by Howard in which he reported 
a condition in the brood of bees as a new disease. Since the term 
" pickled brood" is so frequently used in beekeeping literature it 
may be well to consider Howard's work somewhat in detail. 

The trouble which he calls pickled brood he says had often been 
mentioned by writers in bee papers. Two years before his paper 
was written he himself had two colonies to die during the winter, and 
when in the spring the combs were examined they were found to be 
moldy, especially those containing pollen. These combs were given 
to other colonies with no bad results, until the brood which was being 
reared was about ready to be capped. By watching this brood he 
observed that it did not decay like "foul brood." When the larvae 
are dead, he says, they have a swollen appearance, with neither end 
touching the cell as a rule. After a few days some of the larvaB settle 
down and change to a dark brownish mass which is watery, not ropy, 
and without odor. 

From the combs and dead brood there was isolated a species of 
fungus to which he ascribed the cause of the trouble, and to which 
he gave the name Aspergillus pollini. Concerning his convictions as 
to the etiological relation existing between the fungus and the 
disease he writes: "Several experiments were made during the sum- 
mer which fully satisfied me that my conclusions were correct." 
This condition suggested to Howard the possibility of its being the 
form of foul brood which responds to the shaking treatment and the 
drug method, and the form which disappears of itself when fresh 
pollen is consumed by the bees. He says that the fungus finds a 
good medium in food which contains pollen in the alimentary canal 
of the larvse. The fungus, he says, breaks through the wall of the 
alimentary canal, permeates all the liquids of the body, and there 
produces acetic acid. The larva dies in about three days and is 
pickled in its own juices containing this acetic acid. Such a supposi- 
tion suggested to Howard "pickled brood" as a name for the disease. 
On account of the acid reaction of the larva? thus "pickled," he 
believed that no putrefactive germs entering from the air could grow 

i Howard, Dr. Wm. R., September 10, 1896. A new bee-disease— pickled brood or white fungus. Ameri- 
can Bee Journal, vol. 36, No. 37, pp. 577-578. 



HOWARD, SEPTEMBER 10, 1896. 43 

and cause putrefaction of the tissues, and for this reason no odor was 
present. He includes in his paper a differential diagnosis between 
foul brood and pickled brood. 

In foul brood, he says that the brood is attacked at all ages, from 
two to three days after hatching until after it is capped, and that as 
much brood dies before the feeding of pollen as afterwards ; that the 
brood is attacked by the putrefactive germs from the air, causing 
rapid decomposition, resulting in a ropy brownish mass that gives off 
a very foul odor; that the cappings of the sealed cells are usually 
ruptured by the gases generated within the cell, and that the larvae 
are found in a shapeless mass lying on the lower side-wall of the cell 
and closely adhering to it. Furthermore, he says that when gelatin 
and potato are inoculated with a culture of Bacillus alvei, growth at 
once takes place, forming a viscid ropy liquid which gives off an 
offensive odor resembling foul brood, and when such cultures are 
exposed to putrefactive germs a growth of such bacteria takes place. 

In pickled brood, on the other hand, he says that the brood is 
attacked only after the pollen is mixed with the liquid food, and it 
dies usually just before reaching the pupal stage, but that it may 
pass into this stage and be sealed before being overcome by death. 
No brood, he argues, dies before the age of feeding mixed food arrives. 
Being in this acid or pickled condition, the brood is not attacked by 
putrefactive germs, and, therefore, no decomposition takes place. 
There is a watery condition of the brood. The larvae may be of a light 
brown color, but generally are white, and no odor is present. The 
capping is not ruptured in the brood that is sealed. The brood has a 
swollen appearance, does not stick to the cell wall, and often does not 
lose its shape. Furthermore, he argues that if brood is placed in a 
medium of sweetened water in which starch or wheat bran is mixed, 
and placed in a moist chamber within a dark room, growth of the 
fungus takes place and covers the surface of the medium. The 
medium becomes acid, and when such a culture is exposed to the air 
putrefactive germs do not attack it. 

In this paper the following points are observed : 

1. Howard used the term "pickled brood" for a disorder which 
was clearly different from "foul brood." 

2. He gave a brief but fairly satisfactory description of the gross 
symptoms of the condition. 

3. He claims that the disease is a specific infectious one. 

4. He declares that the cause of the disease is a fungus which he 
isolated from larvae dead of the disease and to which he gave the 
name "Aspergillus poUiniT 

5. The experimental data by which he was supposed to have 
proven that Aspergillus pollini is the cause of the pickled brood, 



44 HISTORICAL NOTES ON BEE DISEASES. 

although not included in his paper, was, as he says, satisfactory to 
himself. 

6. The description which Howard made of the fungus is not suf- 
ficient to identify it. 

One at once observes that Howard brought forth no convincing 
evidence that the disorder with which he was working was infectious, 
nor that the fungus which he named Aspergillus pollini was a new 
one, nor did he prove that any etiological relation existed between 
the fungus and the disorder. 

Inasmuch as the disorder winch Howard described was declared by 
him to be due to a fungus, Aspergillus pollini, it is certain that the 
disease known to bee keepers as pickled brood is not the " pickled 
brood" of Howard. It is the opinion of the writers that the " pickled 
brood " described by Howard does not exist. 

Howard, February 15, 1900. 

Another paper * by Howard appeared in 1900, discussing still an- 
other disease which he supposed was not "foul brood. " The disease, 
as will be learned later, was in all probability European foul brood. 

He quotes a description of this disease by Mr. N. D. West, an able 
bee inspector of the State of New York. In this quotation Mr. West 
says that the disease appears in the spring about the time the apple 
is in blossom, breaking out all at once and spreading with amazing 
rapidity. The young larva has a yellow speck on the body, about 
the size of a pinhead. The older larvae are lengthwise in the ceil, 
white, and uncapped. After dying the brood is either removed 
by the bees or flattens out and becomes at first a cream-colored and 
later a coffee-colored mass. Later in the season some brood, which 
had died after capping, becomes coffee colored and of the consistency of 
heavy honey. When this is tested with a toothpick, the decaying 
mass stretches out to the extent of one-half inch to 1 inch. In some 
cases the odor is sour, while hi others cases, especially if the capped 
stage has been reached by the dead brood, it has a somewhat rotten 
odor. The odor is not especially disagreeable at any time. The 
colony either dies out entirely from this disease, or the condition 
improves so that later in the summer no diseased brood can be found. 
With plenty of stores and a good flow, the disease seems to abate. 

Mr. West's many years of experience as a bee keeper, his experience 
as an inspector of apiaries, and his ardent enthusiasm on questions 
relating to bee diseases, make his description of the appearance of 
this disease of much value. 

Although Howard quotes from West the symptoms that are found 
in the so-called black brood, one finds him deviating far from them hi 

i Howard, Dr. Wm. R., February 15, 1900. New York bee disease, or black brood. Gleanings in Bee 
Culture, Vol. XXVHI, No. 4, pp. 121-127. 



HOWARD, FEBRUARY 15, 1900. 45 

stating his own conception of the disease. In giving his own view 
of the symptoms of the disease, and in pointing out the differences 
which he supposed existed between " black brood," "foul brood," 
and " pickled brood," the writings of Howard indicate, as is evi- 
denced by the following quotation, that he himself had a very inaccu- 
rate conception of the br od diseases of bees. 

SYMPTOMS AND COURSE. 

Brood is usually attacked late in the larval life, and dies during pupation, or later 
when nearly mature and ready to come forth through the chrysalis capping. Even 
after leaving the cell they are so feeble that they fall from the combs helpless. Most 
of the brood dies after it is sealed. In this it is much like pickled brood, except that 
as much or more brood dies in the late larval stage than in the pupa. In foul brood, 
while brood of all ages dies, yet more dies "at the ages of 6, 7, 8, and 9 days than at 
any other age " (author's Foul Brood p. 46), even before the rich chyle-like food mixed 
with pollen is given, which is such a necessary environment for pickled brood and 
black brood. 

When the larvae show the first signs of this disease, there appears a brownish spot 
on the body, about the size of a pinhead. The larvae may yet receive nourishment 
for a day or two; but as the fermentation increases the brownish spot enlarges, the 
larva dies, stands out, swollen and sharp at the ends. In this they are like pickled 
brood, except that the brown spot is not present in pickled brood, but pickled brood 
sometimes becomes brown after death. Foul brood turns brown only after the action 
of the putrefactive germs have brought about decomposition. No decomposition 
from putrefactive germs takes place in pickled brood. In black brood the dark and 
rotten masses, in time, break down and settle to the lower side of the cells, as a watery, 
syrupy, granular liquid — not the sticky, ropy, balsam or glue-like semi-fluid substance 
of foul brood. It does not adhere to the cell walls like that of foul brood; has not the 
characteristic foul odor which attracts carrion-flies, but a sour, rotten-apple smell, 
and not even a house-fly will set her foot upon it. Cappings in foul brood are sunken 
in the center when broken, sometimes puffed out by internal gases. In black brood, 
the cap is disturbed from without, sometimes uncapped, and cell contents removed 
by the bees; not so in foul brood. The cap in pickled brood is usually undisturbed. 
The decayed brood masses do not adhere to the cell walls like either of the others. 

The defect in Howard's description of the appearance of the brood 
which has probably caused the greatest confusion has reference to the 
color of the larvae dead of the disease. In the following quotation 
he mentions the dark and black color of the brood, which according 
to him was so marked that it suggested the name "black brood." 

On account of the character of the dead brood; its beginning with a dark spot on the 
larva, which increases in size, becomes darker, and finally black, for convenience and 
brevity the name black brood has been suggested, and this name is used in the text. 

Since the so-called black brood is in all probability European foul 
brood, many bee keepers expect to find black larvae in this disease. 
Occasionally some of the larvae may be black, but black larvae are 
seldom found. If the bee keeper will bear this fact in mind he will be 
very much aided in understanding the brood diseases of bees. 

From samples of the so-called black brood, Howard reports that 
he isolated two new species of bacteria. The one he named Bacillus 



46 HISTORICAL NOTES ON BEE DISEASES. 

milii and declared it to be the specific germ of " black brood"; the 
other he named Bacillus thoracis and thought probably that it modi- 
fied the disease in some way. He said so little about either of these 
species that neither of them can be identified from his writings. In 
his examination of five specimens received from West, he reports 
Bacillus milii in all of them, Bacillus thoracis in two, and Aspergillus 
pollini in two. 

In his experimental investigations Howard used two nuclei which 
were free from disease, and fed each of them a culture of " Bacillus 
milii" in one-half pint of sirup on November 7, and repeated similar 
feedings on November 10. The feeders were removed from each 
hive on November 12. When the bees were examined on November 
26, no brood at all was found in one of the nuclei. In the other 
nucleus was found no eggs, but larvae six or seven days old and con- 
siderable capped brood. Near the outer part of the brood-nest 
apparently some capped cells were found from which were taken 
nearly matured pupae. Other pupae, nearly white, with a dark 
spot on the abdomen, were removed, together with others which 
were dark or black all over. u Bacillus milii" was reported to have 
been found microscopically in nearly every pupa examined. Howard 
states that no uncapped larvae seemed from gross appearance to 
be affected, but in the bodies of several of them Bacillus milii was 
found. The two nuclei were again examined on December 14. As 
before, there was nothing wrong apparently with one nucleus. In the 
other nucleus there were about 30 capped cells winch contained 
dead pupae that were nearly black. Microscopic examination 
caused him to report the presence of Bacillus milii in all of these 
pupae. 

It will be observed that the results which Howard obtained from 
the inoculation of the two nuclei with cultures of "Bacillus milii 11 
neither proved nor disproved the causal relation of "Bacillus milii" 
to u black brood." As evidence to support his declaration that 
Bacillus milii is the specific cause of black brood, modified probablv 
at times by Bacillus thoracis, he offers the data that Bacillus milii 
was found in all of the few samples which he examined, and that 
in a few instances Bacillus thoracis was also present. 

In pointing out the differences between "foul brood," "pickled 
brood," and "black brood," the following three assertions are made 
by Howard; not one of them, however, has yet been demonstrated 
to be true. 

Foul brood, pickled brood, and black brood. Foul brood, due to Bacillus alvei — 
a specific bacterium. 

Pickled brood, due to Aspergillus pollinis — a specific fungus. 

Black brood, due to Bacillus milii, modified, perhaps, by Bacillus thoracis, specific 
bacteria. 



HOWARD, FEBRUARY 15, 1900. 47 

Summarizing this paper by Howard the following points might be 
mentioned : 

1. Howard received during the year 1899 a few samples of a 
brood disease, principally through Mr. West, of New York State. 

2. He reported that the disease was a new one and gave to it the 
name "New York bee disease" or " black brood." 

3. From the samples of the disorder he claims to have isolated 
an organism to which he gave the name Bacillus milii. 

4. He made no description of "Bacillus milii" by which it is 
possible to identify the organism positively. 

5. He claims that "Bacillus milii" is the cause of the disorder 
which he studied, and in support of it he relates some experimental 
work. 

6. He says that "Bacillus milii" may be accompanied by another 
species, "Bacillus thoracis," which may assist in the destruction of 
the brood. 

This concludes our consideration of three papers written by 
William R. Howard. 

Reviewing the writings of William R. Howard, one learns that 
they have caused no small amount of confusion in the minds of bee- 
keepers respecting the brood diseases of bees. Howard claimed to 
have found Bacillus alvei in that form of foul brood characterized by 
a ropiness, and asserted that that organism is the cause of the disease. 
He gave the name " pickled brood" to an apparent disorder of bees 
which, he says, had often been mentioned in the writings of bee- 
keepers. He asserts that this " pickled brood" is due to a fungus 
to which he gave the name Aspergillus pottini. He called the disease 
about which Cheshire and Cheyne had already written (p. 25), 
" black brood." He declared the disorder to be due to a micro- 
organism to which he gave the name Bacillus milii. The incomplete 
description which Howard made of the species, however, does not 
make it possible to identify such an organism. 

The authors of this paper have received some evidence, however, 
as to the identity of Howard's Bacillus milii. Howard sent bouillon 
and agar cultures of what he claimed was Bacillus milii to one of his 
correspondents stating that it was possible that the culture was not 
pure. Accompanying the cultures was a stained cover-glass prepara- 
tion which he said was prepared from the vegetative form of the 
bacillus. The cultures, together with the stained preparation, 
were forwarded to us. In the cultures was found only Bacillus alvei. 
The stained preparation contained apparently only spores (not 
vegetative forms), and as far as it is possible to know from a micro- 
scopical examination these spores were the spores of Bacillus alvei. 
Such facts should dispel any particular anxiety one might possess 
concerning the existence of such an organism as Bacillus milii. 



48 historical notes on bee diseases. 

Harrison, December, 1900. 

The next paper to be considered is one by Harrison. 1 In comment- 
ing upon the work of Cheshire and Cheyne, he asserts that these men 
established the causal relation of Bacillus alvei to foul brood by 
successfully applying Koch's rules in their work. He rehearsed in 
his paper the spraying experiment which Cheshire was supposed to 
have done and stated that since that time Bacillus alvei has generally 
been regarded as the cause of the disease. 

In the beginning of his work, then, Harrison, like Mackenzie, 
accepted the work of Cheshire and Cheyne as conclusive that Bacillus 
alvei is the cause of foul brood. It is very unfortunate that these 
two men should have made this mistake, as their papers have had 
the effect of strengthening two erroneous ideas : First, that the two 
maladies which together were known as foul brood were one disease; 
and second, that Bacillus alvei is the cause of the disorder. 

Harrison was aware of the fact that some bee keepers believed 
that there was more than one disease included under the name foul 
brood, since, in commenting on the work of JDickel and Klamann, he 
states that Dickel writes of one form of the disease which affects 
the unsealed brood, and of another form which affects the sealed, 
and even a third form, a mixed form which seems to be still more 
malignant. He states furthermore that Klamann suspected two 
kinds of disease. 

Harrison entertained the following ideas concerning foul brood. 
The disease affects chiefly the larvae, and when they are attacked 
they no longer lie curled up in the cell but are extended in it or move 
about unnaturally. The adult bees by a sort of inertness which seizes 
them may at this time show symptoms of the disease. The affected 
larvae become flabby and die, and as a result of the decomposition 
which sets in, the decaying mass takes on a yellowish color. The 
yellow turns to a brown and when touched by a pin at this time or 
later, a portion of the mass may be pulled out in a long, ropy, tena- 
cious string. This ropy mass dries down gradually to a brown scale 
which adheres to the wall of the cell. The bees as a rule are not 
active in removing larvae dead of this disease from the cells, but, on 
the contrary, they are quite inactive, without desire to fly, but they 
may be seen fanning at the entrance of their hive. At this time a 
foul odor may be detected coming from the hive. The phase of the 
disease which some authors discuss as being a different form, Har- 
rison states, is the same disease but that the larvae die after being 
capped over instead of before. The capping of the cells containing 
such larvae becomes indented or sunken and finally perforated. By 

i Harrison, F. C, B. S. A., December, 1900. Foul brood of bees. Bulletin 112, Agricultural Collegeand 
Experimental Farm. Pp. 32. Toronto. Portions of this bulletin are quoted in Bulletin No. 70, Bureau 
of Entomology, U. S. Department of Agriculture, pp. 23-26. 



HARRISON, DECEMBER, 1900. 49 

inserting a pin in either of these cells the same ropy mass may be 
drawn out. If an examination is made of the juices of the larvae at 
different stages of the disease the bacilli may be seen. Spores form 
only after the death of the larvse. The ropy decaying mass as well 
as the scales contain large numbers of these spores. 

Weighing these facts it seems quite probable that Harrison was 
working with but one disease, American foul brood. In his exami- 
nation of the ovaries of queens taken from foul-brood apiaries, 
Harrison reports the rinding of bacilli in three queens. He reports 
that he found bacilli in a larger number of eggs laid in an affected 
colony, and writes: 

In view of these facts, I am of. the opinion that the eggs of bees from diseased hives 
may in some instances be infected. 

Harrison did not find Bacillus alvei in any case of chilled brood 
which he had examined and states that Mackenzie performed several 
experiments with chilled brood and never found this' organism in 
any case where the brood had not been inoculated experimentally. 
Harrison writes as follows concerning the distribution of the disease: 

I have examined diseased larvae from Canada, from Europe (France, Switzerland, 
Austria, Germany, Italy and England), Cuba, and 13 States of the Union, ranging 
from New York to California and from Michigan to Florida, and have succeeded in 
isolating B. alvei from all of them. It is true that some of the cultures show certain 
differences, but they have not been sufficiently pronounced to constitute even a well 
marked variety of the species. 

Harrison may have isolated Bacillus alvei in limited numbers from 
material received from all these sources, but from his description of 
Bacillus alvei one can not be sure that he always identified his culture 
correctly. 

It may be well at this point to consider Harrison's description of 
the organism which he identified as Bacillus alvei. In an abridged 
form it is as follows: 

Occurrence. — Found in larrse of bees suffering from a disease known 
as foul brood. 

Gelatin plates. — The appearance of the growth depends upon the 
age of the colonies and character of the medium. In 24-36 hours 
at 22° C. the colonies are observed to be small, oval, or lozenge- 
shaped, bearing peculiar shoots extending frequently from one end 
and giving it a pear-shaped appearance. At the end of 48 hours the 
colonies are larger, with fine projections shooting out in all directions 
and forming circles. Later this appearance is destroyed by the 
liquefaction of the gelatin. 

Agar plates. — In 12 hours at 37° C. the colonies are small and burr- 
like. Further, concerning the growth on agar, he writes : 

On agar plates streaked with a light inoculation, most beautiful forms occur. The 
growth of the bacilli spreads over the surface and branches repeatedly, giving the 
13140°— Bull. 98—12 4 



50 HISTORICAL NOTES ON BEE DISEASES. 

appearance of seaweed. This appearance is distinctively characteristic; and as the 
growth is very rapid, this method commends itself for making a quick diagnosis of the 
presence of the bacillus in larvae supposed to be diseased. 

Morphology. — A slender bacillus with slightly pointed but rounded 
ends. They usually occur singly, but may form chains of various 
lengths. This species possesses a single flagellum at a pole. No 
capsule has been demonstrated. 

Spores. — The spores are about 2 [i in length and 1 fi in breadth. 
Under favorable conditions they begin to germinate in about three 
hours. 

Motility. — They are actively motile, especially in fresh cultures. 

Oxygen requirements. — Harrison agrees with Cheyne (p. 31). 

Bouillon. — In 14 hours at 37° C. there is a slight cloudiness, in 24 
hours the culture is turbid, and in 48 hours the turbidity is further 
increased and a pellicle begins to form. After 96 hours the broth is 
rather clear, with a white, rather massive, and somewhat tenacious 
pellicle. Reaction of the medium after 10 days has changed from 
+ 0.08 to the neutral point. 

Glucose. — Growth heavier in this medium than in plain bouillon. 
Reaction in 10 days is acid, having changed from +2 to +4.6. 
Involution forms may occur. They are slightly curved and average 
5 p. in length. 

Lactose. — The growth resembles that in plain bouillon, but is 
slightly heavier. Acid is produced but less in quantity than in 
glucose. 

Saccharose. — Turbidity is greater than in any other bouillon and 
more acid is produced. 

Potato. — Harrison writes: 

On potatoes the growth differs considerably, according to the reaction and age of 
the potato. Sometimes a brownish wrinkled growth forms, which gives off a peculiar 
odor; at other times a dryish yellow layer appears. 

Milk. — At 37° C. coagulation of the casein occurs in three days. 
The medium becomes yellowish in color and gives off a peculiar odor. 
The coagulum finally digests, leaving a wheylike fluid. 

Blood serum. — Growth takes place slowly. Many long filaments 
are common, which may be wavy and which may vary in thickness. 
The serum is liquefied. 

Gelatin tubes. — On the surface in three days there occurs a ramifying 
growth. In five days the entire surface is liquefied. A whitish 
growth takes place along the line of puncture, from which numerous 
shoots branch out in the gelatin in all directions. This gives a hazi- 
ness to the medium, which now begins to liquefy. 

In the description which Harrison made he quotes rather freely 
from Cheyne. Some of his statements suggest that at least part of 
the time he was working with other species than BaciUus alvei. 



HARRISON, DECEMBER, 1900. 51 

One polar flagellum (p. 56) does not apply to Bacillus alvei. A 
heavy, tenacious pellicle does not suggest Bacillus alvei. The lique- 
faction in five days of the surface gelatin in tubes containing this 
medium does not suggest Bacillus alvei. The surface growth on 
agar, which Harrison describes as resembling " seaweed," is not 
encountered in the study of Bacillus alvei. These last three cultural 
characters are observed, however, in members of that group of 
bacteria of which Bacillus A (p. 76) is a member. 

Harrison used cultures which he identified as Bacillus alvei in per- 
forming a number of laboratory experiments bearing directly upon 
the treatment of foul brood. His object was to determine the anti- 
septic value of various drugs for this species. The results obtained 
by this method of testing the antiseptic value were reported for weak 
solutions of salicylic acid, camphor, thymol, carbolic acid and tar, 
creolin, eucalyptus, beta naphthol, naphthalene, and formic acid. 
In doing this the drug to be tested w T as added to agar. The agar 
was inoculated with a pure culture of the organism, and observations 
were made as to whether a growth took place on this medicated 
medium. 

Harrison gives the results of experiments in which he used two 
colonies of bees to test the value of naphthol and formic acid in the 
treatment of foul brood. The results which he obtained, however, can 
have only a relative value in treatment, since the organism with which 
he worked has most likely no etiological relation to any disease, or 
at least an unimportant one. Harrison had reached the conclusion 
that considerable attenuation in cultures of B. alvei may take place 
by its prolonged growth on artificial media. Since old cultures on 
this ground might be objectionable, he used, in his experimental 
inoculation, cultures which were only three generations from the 
diseased larvae. 

The further technique, in the carrying out of his experiment, 
involved the feeding of the spores from cultures to each of two 
healthy swarms placed side by side. The spores were scraped from 
the surface of an agar slant, put into 10 cc. of water, and well shaken. 
This suspension was then poured into medicated sirup. One colony 
was fed sirup containing the spores of B. alvei and one-third of a 
grain of beta naphthol to 1 liter of the sirup. The other colony was 
fed sirup containing the spores of B. alvei to which about 1.8 cc. of 
formic acid to a liter of sirup had been added. In both cases the 
medicated and inoculated sirup was taken up readily by the bees. 
The feedings were continued for three weeks, feeding four times per 
week. Each colony received in this way the growth from 12 agar 
slants. During the feeding period the combs containing the brood 
were examined, but no typical symptoms of the disease appeared. 
Cultures of B. alvei were obtained, however, from different parts of 



52 HISTORICAL NOTES ON BEE DISEASES. 

the hive and from the digestive tract of the workers. After the third 
week, to each colony the feeding of ordinary unmedicated sirup 
containing the spores of B. alvei was practiced. In each experimental 
colony typical symptoms of the disease are reported to have been 
observed in 10 days, and a well-established disease after 16 days. 

This experiment is offered as proof by Harrison that the feeding 
of an antiseptic in the treatment of foul brood is beneficial, as it 
hinders the germination of the spores of B. alvei. This confirms, 
he states, the opinion of Lortet that the digestive canal of the nurse 
bee is alone affected. Harrison reports the finding of B. alvei in the 
digestive canal of adult bees taken from diseased colonies. 

After giving the results of his experiments, Harrison writes the 
following conclusion: 

From the results of the above experiments I conclude that in certain cases the use 
of chemicals is beneficial, but I would not say that other measures, such as starvation 
and stamping out, should be abandoned as unnecessary or useless. Some of the drugs 
used are of very little, if any, value; but others, such as formic acid and napthol B, 
are undoubtedly very useful. In some cases, especially those in which the disease 
is very virulent, it may be advisable to resort to more drastic measures. 

In another experiment he reports that symptoms of the disease 
were produced after 14 days when B. alvei was fed. In these inocu- 
lation experiments, cultures were used which had been recently 
isolated in order that the virulence might not be diminished. He re- 
ports one experiment, however, in which cultures were used which 
had been transferred 30 times, with the result that several weeks 
elapsed before the disease appeared and then only in a light form. 

One observes here that Harrison reports at least four cases in 
which foul brood developed after feeding the spores of B. alvei in 
sirup. These are of special interest inasmuch as many failures have 
been made since that time to obtain the symptoms of foul brood by 
similar inoculations. It would be well if Harrison could repeat these 
feeding experiments for confirmation. 

The following summary contains some of the features of interest in 
Harrison's paper: 

1 . It has now been 1 1 years since the bulletin by Harrison, which 
is here briefly reviewed, was published, and very naturally, as its 
author no doubt will agree, it is in need of revision. 

2. He has given in the historical resume a brief account of the re- 
sults and beliefs of a number of workers and writers on foul brood. 

3. He believed that the two forms of foul brood described by some 
authors were only two phases of the same disease, one form being 
that phase of the disease in which the larvae die just before capping, 
and the other one that phase of the same disease in which the brood 
dies after capping. 



LAMBOTTE, SEPTEMBER 25, 1902. 53 

4. He gives a geographical distribution of foul brood, having deter- 
mined it by the isolation of B. alvei from diseased larvae. 

5. He reports the finding of Bacillus alvei in the ovaries of queens, 
and concludes that the eggs in diseased hives might sometimes be 
affected. 

6. He has given quite a lengthy description of B. alvei. 

7. He was not able to isolate B. alvei from chilled brood as the con- 
dition is found in the apiary. 

8. He performed various experiments to prove the value of drugs 
in the treatment of foul brood, with the conclusion that drugs in 
certain cases — for example, formic acid and beta-naphthol — are 
undoubtedly very useful, while some others are of very little or no 
value. 

9. He also reports the successful production of the disease with 
typical symptoms by feeding the spores from pure cultures of B. alvei. 

10. He mentions no difficulty in obtaining B. alvei from "foul- 
brood" material. 

The authors of this bulletin disagree with nearly all of the points 

made by Harrison. His failure to recognize the fact that the mass 

of spores, which are always seen in brood dead of American foul brood, 

do not grow when plate cultures are made, was fatal to his work. 

Occasionally colonies of Bacillus alvei do appear on plates, made from 

this disease, but when they do they appear only in relatively small 

numbers. 

Lambotte, September 25, 1902. 

A paper by Lambotte x caused, at the time it was written, con- 
siderable discussion among bee keepers. It caused some comment 
also on the part of others on account of the views which he expressed 
concerning the identity of Bacillus mesentericus vulgaris and Bacillus 
alvei, and the relation of Bacillus mesentericus vulgaris to foul brood. 

In view of the fact that foul brood seemed to appear unexpectedly 
away from all known sources of infection, a beekeeping society peti- 
tioned the minister of agriculture of Belgium to have a new scientific 
study of foul brood made. Lambotte's work is the result of tins 
petition. From requests made through journals, an ample supply 
of foul-brood samples was received. The diseased larvse in capped 
cells were recognized by the darkened, sunken, and usually perforated 
cappings. The brood dead of the disease he describes as being 
yellow or brownish-yellow, viscid, ropy, and emitting a nauseating 
odor. 

From a stained preparation made from ropy larvae, Lambotte 
observed a very large number of spores which he supposed were the 

i Lambotte, Dr. UL, September 25, 1902. Recherches sur le microbe de la "loque," maladie des 
abeilles. Travail du laboratoire de Pinstitut de pathologie et de bacteriologie de I'universite' de Liege. 
Annates de l'Institut Pasteur, Tome XVI, No. 9, pp. 694-704. 



54 HISTORICAL NOTES ON BEE DISEASES. 

spores of Bacillus alvei. When he inoculated gelatin, agar, or bouillon 
with some of this ropy larval mass, no growth took place and when he 
used larvae which were more recently attacked, the same failure to 
obtain a growth was observed. He took these facts to mean that 
there is something present in the foul-brood larvae which prevents, by 
its antiseptic property, the growth of the bacteria. He proceeded, 
therefore, to inoculate a considerable quantity of sterile bouillon, in 
order that the supposed antiseptic present might be diluted, thus per- 
mitting the germination of the spores. By following this technique 
a growth was obtained and he interpreted it to be the growth of the 
spores which he had observed microscopically in such large numbers 
in the diseased brood. 

The bacillus which he thus obtained he isolated in a similar manner 
from a large number of samples of "foul brood," and by a study of 
its morphology and cultural characters Lambotte identified it as 
being the one described by Cheyne as Bacillus alvei. Furthermore, 
he studied the morphology and cultural characters of a number of 
cultures of Bacillus mesentericus, and by a comparison of these with 
those of Bacillus alvei he reached the conclusion that the two are 
very similar. 

To show more conclusively that Bacillus alvei and Bacillus mesen- 
tericus are very similar, Lambotte made use of the phenomenon of 
agglutination. Guinea pigs were used in his experiments. In 
immunizing the animals he used a suspension of an agar culture of 
Bacillus alvei and Bacillus mesentericus, respectively, in physiological 
salt solution. In each case the animal received four inoculations at 
weekly intervals. He reports that the serum of an untreated guinea 
pig did not exhibit, upon examination, the phenomenon of agglutina- 
tion. The serum of a guinea pig, on the other hand, which had been 
treated by inoculations with Bacillus alvei, agglutinated a culture of 
this species at a dilution of 1 to 350, and the serum from the same ani- 
mal agglutinated cultures of Bacillus mesentericus at a dilution of 1 to 
250. Furthermore, the serum of a guinea pig that received the inocu- 
lation of Bacillus mesentericus agglutinated Bacillus mesentericus as 
well as Bacillus alvei at a dilution of 1 to 250. Neither of these two 
sera agglutinated any other bacilli at these dilutions. This caused 
Lambotte to conclude that Bacillus alvei and Bacillus mesentericus 
vulgaris are the same species. 

Having convinced himself that this very intimate relation exists 
between Bacillus alvei and Bacillus mesentericus vulgaris, he at- 
tempted to prove by the inoculation of healthy colonies that foul 
brood could be produced with cultures of Bacillus mesentericus. He 
killed some of the larvae by pricking them and placing a suspension 
of Bacillus mesentericus in the cell with the dead larvse. He hoped 



LAMBOTTE, SEPTEMBER 25, 1902. 55 

that foul brood might be started in the colony, but repeated attempts 
resulted each time in failure. 

He then made a medium from bee larvae by the use of which he 
thought he had obtained by successive inoculation a special variety 
of Bacillus mesentericus. He supposed that if Bacillus mesentericus 
were grown upon the bee-larvae medium its virulence for bees would 
be increased. After using the culture of Bacillus mesentericus, which 
had been grown upon the bee-larvae medium, and after inoculating 
larvae as before, he reports that foul brood was produced with the 
typical symptoms of the disease. The only exception noted was that 
fewer cells were affected. 

He attributed his good results to two facts, first, that Bacillus 
mesentericus was cultivated on a bee-larvae medium, and second, that 
the experimental inoculation was made at a time of the year when the 
activity of the hive was considerably diminished. To the latter 
factor he attributes most of his success. He states that a colony 
inoculated with Bacillus alvei or with Bacillus mesentericus grown on 
a bee-larvae medium will not allow itself to become infected when it 
is active at the beginning of the season. 

In his conclusions Lambotte writes: 

(1) Bacillus alvei, described by Watson Cheyne and Cheshire as the specific cause 
of foul brood, is simply the widely distributed organism Bacillus mesentericus vulgaris. 

(2) Bacillus mesentericus can be found in healthy hives, in the cells of the comb, and 
in the intestines of bees. 

(3) Bacillus mesentericus, by growth in the tissues of larvae, produces changes char- 
acteristic of foul brood. 

Lambotte insists that the hygiene of the colony is above all the 
most important in the control of foul brood. He believes that unless 
the resistance of the larvae to infection is maintained by good hygiene, 
Bacillus mesentericus, which is so widely distributed in nature, may 
invade the colony and produce foul brood in any apiary. 

A brief summary of Lambotte's works may be made as follows: 

1. He did not take into consideration the two forms of foul brood 
described by some authors, working for the most part, at least, with 
American foul brood only. 

2. He observed that in American foul brood it was not easy to 
obtain a growth of the spores which are found in such large numbers 
on microscopic examination. 

3. He suspected that an antiseptic was present in the dead remains 
of the larvae in this disease which prevented the growth of the spores. 
The effect of such an antiseptic he hoped to overcome by diluting it 
with a large amount of the medium used for its cultivation. 

4. He obtained a bacillus by this special technique and identified 
it as the Bacillus alvei of Cheyne and Cheshire. 



56 HISTORICAL NOTES ON BEE DISEASES. 

5. He compared Bacillus alvei and Bacillus mesentericus vulgaris 
and arrived at the conclusion that they are one species and offered 
as proof of it that the morphology and cultural characters of the 
two are similar, and that the serum of an animal immunized with 
Bacillus alvei will agglutinate Bacillus mesentericus vulgaris and vice 
versa. Furthermore, he claimed that foul brood can be produced 
with cultures of Bacillus mesentericus vulgaris. 

6. He believed that when the resistance of the larvae is for any 
reason lowered Bacillus mesentericus, if introduced, can become viru- 
lent and produce "foul brood." In this way he explained the pres- 
ence of ' 'foul brood" in an apiary without the introduction of infective 
virus from without. 

This work of Lambotte has been criticised by different writers since 
its appearance. The spores which he observed to be difficult of 
germination were most likely not caused to germinate by the tech- 
nique which he used. It would seem also that he was in error in 
concluding that Bacillus mesentericus and Bacillus alvei are one 
species. This conclusion led him to the unlikely supposition that 
"foul brood" might appear in any apiary without the introduction 
of an infective virus other than the widely distributed and commonly 
met with organism Bacillus mesentericus vulgaris. 

Harrison, February 28, 1903. 

In a review, Harrison 1 disagrees with some of the views expressed 
in Lambotte's paper (p. 53). He did not believe with Lambotte that 
B. alvei and B. mesentericus vulgaris are one species. It was his 
opinion that Lambotte's work on these two species was insufficient 
to establish their identity. Harrison compared the descriptions of 
the two species made by different authors and offered the results as 
evidence that the two were different. In offering the evidence he 
states that he did not have time himself to make, for comparison, a 
study of the cultures themselves. Harrison was led to believe that 
Lambotte began his experiments with Bacillus mesentericus vulgaris 
and not with Bacillus alvei. 

Two minor points of considerable interest are also recorded : First, 
Harrison at this time states that he too had had at times some diffi- 
culty in obtaining a growth from the spores in "foul brood"; and 
second, he now credits Cowan for having said that Bacillus alvei pos- 
sessed but one flagellum. 

The following sentence from Harrison's paper is offered as an argu- 
ment to disprove the identity of Bacillus alvei and Bacillus mesen- 
tericus vulgaris: 

1 Harrison, F. C, February 28, 1903. Bacillus mesentericus et B. alvei. Revue Internationale d'Apicul- 
ture« Tome XXV, No. 2, pp. 29-32. 



HAKRISON, FEBKUARY 28, 1903. 57 



If Dr. Lambotte's theory that Bacillus mesentericus vulgatus and Bacillus alvei are 
identical is true, we should naturally expect to find cases of foul brood arising spon- 
taneously in countries which never import bees or material from infected localities. 

This assertion could be admitted as evidence if Bacillus alvei were 
known to have as important an etiological relation to foul brood as 
Harrison supposed that it had (p. 48). One of the facts which 
prompted Lambotte's investigation was that the disease seemed to 
break out independently of any source of infection. If any casual 
relation does exist between Bacillus alvei and any form of foul brood, 
and if his theory concerning the identity of Bacillus alvei and Bacillus 
mesentericus vulgaris can be established, Lambotte offered a very 
clever explanation for the existence of the apparently sporadic cases 
of the disease. 

It is not likely that Lambotte produced foul brood with either 
Bacillus alvei or Bacillus mesentericus vulgaris. The two species are 
most likely different species, but the evidence advanced by Harrison 
to prove that the two are different is inferior to that which Lambotte 
produced to establish their identity. Lambotte made his greatest 
error apparently in faulty observations. 

In the opinion of the writers, both Harrison and Lambotte were 
probably describing their experiences with American foul brood, and 
the spores which they saw in such large numbers were those of 
Bacillus larvse. The growth which they obtained was not a growth 
from these spores, but a growth of Bacillus alvei or a member of the 
group to which Bacillus mesentericus vulgaris (Bacillus A, p. 76) 
belongs. Either of these species may be present but occur most 
always in small numbers. 

Another point of considerable interest might be mentioned here. 
In a paper by Harrison 1 presented to the Bee Keepers' Association 
of the Province of Ontario in November, 1904, the following is found: 

Two years ago I remember there was some talk of black brood, and I think a com- 
mittee was appointed to send samples to me. Whether they did not meet with any 
cases of black brood or no I don't know, but I know I have received no samples, * * * . 

This statement tends to confirm the suspicion already expressed 
that Harrison was working with American foul brood. 

In an address 2 delivered in November, 1905, before the Bee 
Keepers' Association of the Province of Ontario, Harrison announced 
to the association that he was leaving his position as director of the 
association and representative of the agricultural college. Since that 
time we have not learned of any work on bee diseases published by 

1 Harrison, F. C, 1905. Diseases of bee larvse. Annual Report of the Bee Keepers' Association of the 
Province of Ontario, 1904. Toronto, pp. 27-36. 

2 Harrison, F. C, 1906. Diffusing apicultural knowledge. Annual Report of the Bee Keepers' Associa- 
tion of the Province of Ontario, 1905, pp. 8-10. Toronto. 



58 HISTORICAL NOTES ON BEE DISEASES. 

him. It is to be regretted if the duties in his new position limit his 
activity in this line of research. 

Moore and White, January 15, 1903. 

In the spring of 1902 Moore, assisted by one of the writers of this 
bulletin, began the investigation of the bee diseases that were present 
in the State of New York. Neither was familiar with the manifesta- 
tions of the different diseases attacking bees, further than the infor- 
mation which could be obtained from the publications of Cheshire and 
Cheyne, Howard, Harrison, and data obtained directly from the four 
inspectors of apiaries of that State — Messrs. West, Stevens, Stewart, 
and Wright. The samples of brood examined were received from 
these inspectors with the diagonsis of each sample already made. 
The first report * which was made to the commissioner of agriculture 
of that State on the investigation gives a brief account of the exami- 
nation of 10 samples labeled "black brood/' 7 samples labeled "foul 
brood," and 5 samples labeled "pickled brood." 

William R. Howard, it will be remembered (p. 44), received samples 
of diseased brood from N. D. West, of New York. He examined them 
and reported the disease as new, naming it "New York State bee 
disease" or "black brood." He ascribed the cause of the disease to 
a bacillus, to which he gave the name Bacillus milii. The 10 samples 
labeled "black brood," and examined by the authors of the paper 
under consideration, were all from New York State and 7 of them 
were diagnosed by Mr. West. 

The bacterial findings recorded by Moore and White show that 
Bacillus alvei was present in all the samples, while there is no record 
of Bacillus milii in any of them. Other bacteria, which appeared in 
most instances to be micrococci, were occasionally associated with 
Bacillus alvei. The absence of any bacillus corresponding to the 
description of Bacillus milii in these samples of so-called "black 
brood" was strong evidence that such a species was not the cause of 
the disorder. 

The question naturally arose as to whether this trouble was a new 
disease, as Howard had led the people to believe. In forming an 
opinion as to whether a new disease existed, the work of Howard and 
others was considered. Cheshire and Cheyne (p. 25) had described 
the symptoms of "foul brood" and had apparently found Bacillus 
alvei present in sufficient numbers to suspect this species as the cause 
of the disease. Harrison (p. 48) had found a species in "foul brood" 
which he had identified as Bacillus alvei. Lambotte (p. 53) had done 

1 Moore, Veranus A., M. D. , and G. Franklin White, B. S. , January 15, 1903. A preliminary investigation 
into the cause of the infectious bee disease prevailing in the State of New York. State of New York, Depart- 
ment of Agriculture, Tenth Annual Report of the Commissioner of Agriculture, for the year 1902, pp. 
255-260, two plates. 



MOORE AND WHITE, JANUARY 15, 1903. 59 

likewise. Ten samples of diseased brood were therefore examined 
which corresponded in gross appearance to the symptoms of the dis- 
ease which Cheshire and Cheyne reported, and the bacteriological 
examination of these 10 samples revealed the presence of Bacillus 
alvei in numbers sufficient to lead one to suspect a causal relation of 
the organism to the disease. The conclusion that would be drawn 
from these facts regarding the disease, in the absence of Howard's 
work, very naturally would be that it is not a new disease, but simply 
"foul brood." 

It was necessary now to weigh the evidence which Howard pro- 
duced in support of the view that the disease was new. Howard 
received 5 samples from Mr. West and reported the presence of 
"Bacillus miliV in all of them, u Bacillus thoracis" in 2, and "Asper- 
gillus pollini n in 1, but nothing was found in the samples of so-called 
"black brood" received and examined by Moore and White which 
could be identified as either species. The experimental data which 
Howard offered in support of his view was also very unsatisfactory. 

In view of all these facts the authors of the report under considera- 
tion drew the conclusion: "That the prevailing disease [so-called 
black brood] in this State [New York] is very similar to, if not 
identical with, the 'foul brood' of other States, Canada, and Europe." 
This conclusion means that the disease, which the people of New 
York State were taught by Howard to be a new disease and which 
he chose to call "The New York bee disease" or "black brood," is 
not a new one, but is the one which Cheshire and Cheyne agreed was 
"foul brood." 

Various inoculation experiments were now tried for the purpose of 
demonstrating whether or not Bacillus alvei is the cause of a brood 
disease. Several methods of inoculation which had been used by 
others in attempting to produce the disease in healthy brood experi- 
mentally were employed, but always with negative results. The 
most logical way to make the inoculation and the one which might 
be expected to give the most accurate results, very naturally, is by 
feeding the bees. This was tried with the hope that it would give 
the most accurate results. 

The inoculation of one colony only is reported. A colony free 
from disease was fed, on August 4, sugar sirup, to which was added 
the spores of Bacillus alvei taken from agar plates and the vegetative 
form of the same species taken from fresh bouillon cultures. Simi- 
lar feedings were given to the bees three times per week until Sep- 
tember 28, but the symptoms of "black brood" did not appear. The 
results of this experiment, therefore, were negative, as were all the 
others as far as the producing of the disease was concerned. To 
make sure that some of the culture fed had reached the larvae, cul- 



60 HISTORICAL NOTES ON BEE DISEASES. 

tures were made from the larvae before feeding and after feeding. 
Bacillus alvei did not appear on the plates made before the colony had 
been fed the culture, while many appeared on those made after the 
cultures were fed. The culture therefore reached the larvse and no 
disease resulted. While the negative results of these few experiments 
were not sufficient to disprove an etiological relation between Bacillus 
alvei and foul brood, it did cause those doing the work to question the 
experimental results which others had reported. 

The samples of American foul brood which were received and 
examined were labeled "foul brood." Six of the seven samples of 
this disease received gave no growth when cultures were made. 
Concerning the bacteriological findings in this disease the following 
is written: 

Stained cover glass preparations made from the dried dead larvae contained large 
numbers of spores, but they failed to grow in any of our media. 

Since the spores which were found in such large numbers in the 
larvse dead of this disease would not grow, no inoculation of healthy 
brood was attempted. The samples of this disease did not show, 
on examination, the presence of Bacillus alvei. This at once sug- 
gested the fact that the disease is not the one studied by Cheyne as 
foul brood. 

A study of five samples of the so-called pickled brood gave 
practically negative results both microscopically and culturally. 
The point to be noted here is that no fungus was found in this dis- 
order corresponding to the one described by Howard (p. 42) as 
Aspergillus pollini. This fact very naturally suggested the proba- 
bility that Howard had made another error in the determination of 
the cause of a brood disease. 

The report included the study of brood from only three healthy 
apiaries. In samples taken from two of them, Bacillus alvei was not 
found, while a sample from the third apiary which was thought to be 
healthy but in a diseased district, showed the presence of Bacillus 
alvei in considerable numbers. 

The following facts were learned in the investigations just reviewed : 

1. At least two infectious diseases affecting the brood of bees 
exist. This fact had been known, however, for some time by the 
inspectors of apiaries of New York State, and by Dzierzon (p. 18) 
and many others years before. 

2. Howard had erroneously reported European foul brood to be a 
new disease, which he named the "New York bee disease" or "black 
brood." 

3. To produce foul brood in a healthy colony by feeding cultures 
of Bacillus alvei was by no means easy. 



WHITE, JANUAKY 15, 1904. 61 

4. The results reported by others regarding the causal relation 
between Bacillus alvei and "foul brood" were questionable. 

5. The spores found in the brood dead of American foul brood 
would not grow on the media commonly used in the laboratory, 
suggesting the possibility of a new and interesting species. 

6. The disease which was being diagnosed as "foul brood" is not 
the foul brood studied by Cheyne, but is another disease now known 
as American foul brood. 

7. Aspergillus pollini was not present in the samples labeled 
"pickled brood/' meaning that the condition was not Howard's 
"pickled brood," or that he had made another error in his study of 
the condition. 

8. No colonies of Bacillus alvei appeared on the plates made from 
the brood of two healthy apiaries, but colonies of that species did 
appear in considerable numbers on plates made from brood taken 
from a third apiary which was considered healthy, but located in an 
infected district. 

9. Lastly, much work would have to be done on bee diseases before 
the confusion could be cleared up and the causes demonstrated. 

White, Januaey 15, 1904. 

In 1904 another paper * appeared giving the results of some 
investigations on bee diseases made during the summer of 1903. 
The work was a continuation of that done the preceding year. 

It was desirable to know whether Bacillus alvei was constantly 
present in the samples of the so-called black brood. If this species 
could be found in large numbers in every sample of this disease and 
not in other conditions, it would be a valuable means of diagnosing 
the disease as well as suggesting a possible etiological relation 
between the organism and the disease. 

Toward establishing the constant presence of Bacillus alvei in the 
foul brood of Cheshire and Cheyne (the so-called black brood) 
26 samples were examined and Bacillus alvei was found in all of 
them. Twenty-four of the 26 samples were sent by Mr. West, 
but no species was found in any of them which was suspected as 
being Bacillus milii. These bacteriological findings, therefore, 
corroborated the conclusion of the preceding year that the so-called 
black brood is simply the foul brood of Cheshire and Cheyne. 

Inasmuch as the efforts to produce foul brood with cultures of 
Bacillus alvei failed to give positive results in 1902 (p. 59), further 
attempts were made to determine the pathogenesis of this species for 

i White, G. F., January 15, 1904. The further investigation of the diseases affecting the apiaries in the 
State of New York. State of New York, Department of Agriculture, Eleventh Annual Report of the 
Commissioner of Agriculture, for the year 1903, pp. 103-114. 



62 HISTORICAL NOTES ON BEE DISEASES. 

bees. In the feeding experiments of this year some of the brood 
died. This slight difference in the results, from those obtained the 
preceding year, was probably due to the difference in the details of 
the experiment. Although some of the brood was found dead, the 
condition did not present sufficient symptoms, in the opinion of the 
author, to justify him in pronouncing it foul brood. Many punctured 
cappings were observed and dead larvae of a dull color were present. 
These dead larvae were found by cultures to contain Bacillus alvei. 
The death of these larvae might have resulted from chilling or other 
causes, and the cappings may be punctured by the bees in different 
conditions that result in the death of the brood after capping. 

The presence of Bacillus alvei could easily be explained from the 
fact that cultures can be isolated from apparently healthy larvae 
taken from a colony to which the spores of the species has been fed. 
There was also wanting in these dead larvae the yellowish color 
usually observed in those affected with European foul brood. The 
slightly viscid character which is sometimes present in brood dead of 
European foul brood was also absent. The rapidity with which the 
condition disappeared when the days became warmer was another 
indication that the disease was not European foul brood. The 
results of the experimental inoculation of healthy brood with cultures 
of Bacillus alvei were negative, and were therefore similar in this 
respect to those of the preceding year. 

Since a number of articles had appeared about that time advo- 
cating the use of formaldehyde gas in foul-brood treatment, some 
preliminary experiments were conducted to test the efficiency of 
this disinfectant when applied to brood combs. The experiments 
demonstrated that it is not easy to destroy the spores which are 
within the dead larvae and that the gas as it was being applied in the 
treatment of the brood diseases could not be relied upon. 

The samples of American foul brood which were received for 
examination in 1902 were labeled "foul brood" when received. 
From the time Cheshire and Cheyne published their joint paper in 
1885 to 1902 Bacillus alvei was suspected as being the cause of "foul 
brood." Bacillus alvei, however, was not encountered in the samples 
labeled "foul brood" received and studied in 1902 (p. 60). Spores 
were found present in the decaying remains of the dead brood, but 
they refused to germinate on artificial media. 

The first time that these spores were caused to germinate under 
laboratory conditions was in 1903. For this purpose a special agar 
medium was used, made from the larvae of bees. A somewhat similar 
medium had been used by Lambotte (p. 55), but with it he did not 
obtain a germination of these spores. This special agar was used 
in a test tube, and Liborius's method for making inoculations was 



WHITE, JANUARY 15, 1904. 63 

employed. Until the organism could be further described, and until 
there was more evidence that there was a causal relation existing 
between the species and the disease with which it was found asso- 
ciated, it seemed best to refer to the bacterium as Bacterium "X" 
and to the disease as "X brood." Seven samples of this disease 
were studied in 1903, and Bacterium "X" was found by cultures in 
all of them. 

The disease called u pickled brood" received some further study at 
this time. The most striking feature in the results was the record of 
no growth from the cultures. The following is taken from the 
report : 

The results of the examinations showed that "Aspergillus pollinis" was not found. 
Further investigations must be made before any conclusion can be drawn as to the 
real cause of this trouble. 

Concerning paralysis in adult bees, the following was written: 

The disease known to the apiarists as palsy or paralysis attacks the adult bee. 
The name is suggestive of the symptoms manifested by the diseased bee. A number 
of bees affected were received from Messrs. Wright and Stewart taken from apiaries 
in New York State. Bacteriological examinations have been made of a number of 
the bees so affected but no conclusions can be drawn from the results thus far obtained 
as to the cause of this disorder. 

The following is a brief summary of the results obtained during 
the year 1903: 

1. Bacillus alvei was found in all samples of European foul brood 
examined. 

2. A causal relation between Bacillus alvei and European foul 
brood seemed questionable. 

3. Bacillus alvei was not encountered in any sample of American 
foul brood. 

4. The samples of American foul brood did contain, however, a 
species which was referred to as Bacterium "X," in such numbers 
and with such constancy as to suggest an etiological relation to the 
disease. 

5. A growth of this species was obtained on artificial media. 

6. Neither "black brood" nor u Bacillus milii^ was found. The 
work of the year seemed to confirm the idea that the so-called " black 
brood" was simply the foul brood of Cheshire and Cheyne. 

7. The cultural results obtained from the so-called pickled brood 
were practically negative. 

8. The "Aspergillus poUini" named by Howard was not found in 
any disorder of the brood of bees. 

9. A disease called palsy or paralysis by the bee keepers seemed to 
be a malady, but no cause was found. 

10. Formaldehyde gas as ordinarily used in the apiary would not 
insure complete disinfection. 



64 HISTORICAL NOTES ON BEE DISEASES. 

Bahr, 1904. 

A paper on the diseases of bees by Dr. L. Bahr, 1 of Denmark, 
bears the date 1904. The author gives a brief review of the work 
on bee diseases, together with some interesting observations by him- 
self. In that portion of his paper describing his own observations 
the following is recorded : 

A number of samples of brood have been sent to me from various parts of the country 
(Denmark) having the following symptoms: Some of the diseased larvae were quite 
small, while some of them are older — from 4 to 6 days. They never become ropy as 
those of foul brood, but retain their form until they approach the consistency of gruel. 
The color is whitish yellow but sometimes somewhat darker. In the gruel-like mass 
of the diseased larvae I found a very email oval bacterium. 

Bahr mentions that the disease seems to be quite contagious. 
From his description of the disease and from his bacteriological 
findings there is a strong suggestion that the disease to which he 
refers is European foul brood. Sufficient facts, however, are not 
given to make this point at all positive. The author states that his 
studies were not completed. 

Burri, October and November, 1904. 

We shall now consider a very excellent piece of work on foul brood 
by Dr. Burri. 2 In his introductory remarks this author very aptly 
refers to the need and value of a scientific study of foul brood. 

Burri began his work on foul brood apparently in the spring of 1903. 
He observed that the foul odor which is emphasized so much in the 
literature on "foul brood" is not constant for all samples. Studying 
the different samples he concluded that the ropiness of the decaying 
larvae and the tonguelike scales on the lower side wall of the cell were 
characteristic of typical "foul brood." 

He also calls attention to the very large number of spores in the 
decayed foul-brood larvae, and the absence of any vegetative forms. 
Cultures were made from these dead larval remains, but there was no 
germination of the numerous spores. The occasional colony which 
did appear he attributed to an accidental contamination with a 
different species. Failing in his attempt to obtain a growth of these 
numerous spores, Burri came to the conclusion that they were a new 
species that would not grow on the media ordinarily used in the 
laboratory. He added to his medium some cooked healthy larvae 
somewhat similar to the medium used by Lambotte, but with this 
special medium he did not obtain the growth desired. Failing still 
to obtain a growth of the species, he proceeded with the study of its 
morphology as observed in the various stages of decay of the brood. 

i Bahr, L., 1904. Vore Bisygdomme. Foredrag holdt ved DBF's diskussionsm0de i Grejsdalen den 11 
Septbr. 1904. Saertryk af Tidsskrift for Biavl Nr. 16 og 17. 

2 Burri, Dr. R., October and November, 1904. Bakteriologische Forschungen iiber die Faulbrut. Schwei- 
zerische Bienenzeitung, Nro. 10, pp. 335-342; Nro. 11, pp. 360-365. 



BURET, OCTOBER AND NOVEMBER, 1904. 65 

Further attempts were then made to study the species culturally. 
He smeared some freshly infected larvae supposed to contain only 
rods upon a certain medium and obtained spore-bearing rods and 
spores similar to those which had been observed in the diseased 
larvse. He made a similar inoculation from the dead larvae which 
had turned brown and which contained only spores, and as a result 
of this inoculation he obtained motile rods which later formed spores. 
Burri was somewhat inclined to believe that pure cultures had been 
obtained by his method of inoculation, although he states that the 
obtaining of pure cultures of this organism had to remain an unful- 
filled wish. 

From his studies Burri came to the conclusion that the organism 
is neither Bacillus alvei nor Bacillus mesentericus, but a new one. 
He repeated some of the experiments reported by Lambotte (p. 53), 
but was inclined to believe that the latter was in error. Besides 
studying from a number of samples this form of foul brood to which 
he referred as the nonstinking form (most probably American foul 
brood), Burri received and studied other samples of foul brood to 
which he referred as the foul-smelling form (most probably European 
foul brood). In the latter disease he found a large number of bacteria 
unlike those observed in samples of the other disease studied. The 
species which was present in large numbers in the latter samples 
grew without difficulty when sown on artificial media, and he identified 
it as Bacillus alvei Cheshire and Cheyne (p. 25). 

We are not inclined to think of this latter disease (European foul 
brood) as the one which is the more foul smelling of the two, nor the 
former the ropy form (American foul brood) as the less stinking one 
of the two. It is true that only a few of the samples of American 
foul brood have a disagreeable odor when they reach the laboratory; 
nevertheless, the most disagreeable odor encountered in diseased 
brood when it is examined in the apiary is present in those colonies 
that are affected with American foul brood. It is American foul 
brood that the American bee keepers think of when they refer to the 
foul-smelling foul brood. 

Burri encountered other bacteria than Bacillus alvei and the one 
which was difficult of cultivation. He mentions the presence of 
bacteria which he associated with a condition referred to as sour 
brood. He reports that he had always found foul brood present with 
this latter condition. 

The following are the conclusions drawn by Burri in his paper: 

1. There are in Switzerland, and also in other places, at least two distinct kinds of 
bacteria which can produce a typical contagious foul brood. In one case it is Bacillus 
alvei described by Cheshire and Cheyne; in the other a species of bacterium not 
formerly known, which is difficult to cultivate. 
13140°— Bull. 98—12 5 



66 HISTORICAL NOTES ON BEE DISEASES. 

2. The two kinds of foul brood are easily distinguished from each other in the dried 
remains of the larvae. That form of the disease in which Bacillus alvei is found exhibits 
an offensively smelling residue in which microscopically are foimd rods 2 fi in 
length, together with numerous spores. The larval remains in which are found the 
organism that is difficult to cultivate are almost odorless, and on microscopic exami- 
nation spores 15 p in length are recognized, but no rods. 

3. Occasionally other bacteria which stand in a certain relationship to the so-called 
foul-brood germs obtain local significance as the cause of foul brood. Lambotte's 
view, on the other hand, that the potato bacillus (B. mesentericus vulgatus) is to be 
considered the cause of foul brood is yet without demonstration. 

4. In choosing the methods for eradication of the disease, the fact that there are at 
least two kinds of foul-brood bacteria must be taken into consideration. 

5. In every case a certain amount of knowledge of the bacteria in question is desired, 
not only from the scientific but from the practical point of view as well. 

Some of the interesting facts rioted in Burri's paper might be 
summarized as follows : 

1. He recognizes two forms of foul brood. 

2. He refers to the ropy type of foul brood (American foul brood) 
as the non-smelling form of the disease, and to European foul brood 
as the foul-smelling form. 

3. He did not obtain a growth of the spores present in American 
foul brood either on the media ordinarily used in the laboratory or 
on a special medium to which cooked bee larvse were added. 

4. He studied the morphology of the organisms present in the 
foul-brood larvse in a manner similar to that followed by Cheshire 
(p. 19). 

5. He expressed doubt concerning the accuracy of the results 
reported by Lambotte. 

6. In one disease (probably European foul brood) he obtained 
Bacillus alvei in very large numbers. 

7. He found a condition to which he referred as sour brood, and 
with it he found associated a species to which he referred as sour- 
brood bacteria. 

8. In his investigations he says foul brood always accompanied 

sour brood. 

White, January 14, 1905. 

The work on bee diseases was continued during the year 1904 in 
New York State and was followed by another report. 1 The work 
of the year was devoted to the diagnosis of the brood diseases in the 
laboratory; to a study of "foul brood" (European foul brood) and 
"X" brood (American foul brood); and to a study of palsy or paral- 
ysis in bees. 

The similarity that exists between samples of the different brood 
diseases was observed to be so marked at times that a diagnosis of a 
condition often could not be positively made without a bacterio- 

i White. G. Franklin, January 14, 1905. State of New York, Department of Agriculture, Twelfth 
Annual Report of the Commissioner of Agriculture, for the year 1904, pp. 106-107. 



WILSON, 1905. 67 

logical examination. This called for considerable work in diagnosis 
in the laboratory. The results of the examinations showed that 
European foul brood and American foul brood were the diseases of 
bees which attracted most interest in the State. 

Bacillus alvei was found to possess a number of flagella arranged 
peritrichic instead of one flage-Uum at a pole, as Harrison at first 
reported, but later accredited Cowan with the statement (p. 56). 
The fact that Bacillus alvei was supplied by more than one flagellum 
had already been pointed out by Lambotte. 

Concerning Bacillus "X" (Bacillus larvse) the following is found: 

It is a slender rod with moderate motility having a tendency to form in chains. 
The formation of spores and the arrangement of flagella is somewhat similar to that 
found in B. alvei. While B. alvei grows quite well on all the artificial media com- 
monly used in the laboratory, the growth of Bacillus "X v is not so easily obtained. 
The medium which is most successful in the cultivation of this species is the one made 
from the laryse of bees. Growth has been obtained with difficulty upon ordinary 
agar and gelatin. 

The so-called palsy or paralysis received some attention, but after 

beginning this work it was soon realized that before it could be done 

satisfactorily it would be necessary to know something of the normal 

bacterial flora of the healthy bee. A brief study of the bacterial 

species most frequently found within and upon the normal bee was 

therefore made. 

White, June, 1905. 

About the time that this last report was published, a manuscript 
embodying all of the work done on bee diseases at the New York 
State Veterinary College for the State of New York was prepared 
as a thesis. 1 Since the manuscript is available to but few, it will 
not be reviewed here. With very few changes this manuscript was 
published as Technical Series No. 14, Bureau of Entomology, United 
States Department of Agriculture (p. 76). 

Wilson, 1905. 

Of course it is very frequently impossible on account of inadequate 
descriptions to identify certain organisms. In the case of Bacillus alvei 
there is but little excuse for any mistake, since the description which 
Cheyne has made is entirely adequate for this purpose. In this con- 
nection a paper by Wilson 2 is of interest. 

He used a culture for demonstration purposes in a medical school, 
which he isolated from the tonsils of a patient with suspected diph- 
theria and identified it as B. alvei. He claims that B. alvei is fre- 

1 White, G. Franklin. June, 1905. The bacterial flora of the apiary with special reference to bee diseases. 
Thesis, Cornell University, Ithaca, N. Y. • 

» Wilson, Dr. R. J., 1905. Morphological characteristics of the Bacillus alvei. Proceedings of the New 
York Pathological Society, vol. 5, pp. 79-81. 



68 HISTORICAL NOTES ON BEE DISEASES. 

quently seen in cultures from the throat. Now, it may be that Wilson 
made a correct identification, but inasmuch as the source of the 
culture was the throat, he should have been very careful about 
making the identification positive. 

It might be mentioned here that not a few bee keepers have been 
startled by an announcement that B. alvei is found in human sputa. 
Some of them have reasoned, very naturally, that if all reports were 
true the sputum might be the source of foul-brood infection, but 
there is no convincing evidence, of course, that such is the case. 

Burri, January, 1906. 

Burri's next paper 1 was on "foul brood" and "sour brood. " 
His discussion of foul brood is quite similar to that which appeared 
in his former paper (p. 64). We shall therefore direct attention at 
this time to that portion devoted to "sour brood." 

The origin of the name "sour brood" is indefinite. Quoting from 
C. P. Dadant, an American writer, Burri writes that there are three 
diseases of the brood recognized in America — foul brood, sour brood, 
and black brood. This view would make sour brood synonymous 
with pickled brood, but as it will be learned later in his work on sour 
brood, Burri was studying for the most part at least European foul 
brood. 

In his work Burri did not find a uniformity in the diseased brood 
examined either in the gross or the miser oscopic appearance. In 
one sample he found no bacteria, although the outward appearance 
of the larvse indicated disease. In another sample the gross ap- 
pearance did not suggest foul brood, and there were absent the bac- 
teria which are commonly found in the disease; and in their stead 
there were present millions of bacteria which to the investigator did 
not seem to stand in etiological relation to the disease. In still a 
third instance the larvae gave no outward sign of being lolled by the 
bacteria of foul brood, but when studied culturally, they showed 
the presence of a very large number of unidentified bacteria together 
with a few of those which frequently accompany "foul brood." 
These findings illustrate, he says, some of the difficulties which are 
encountered in a study of the brood diseases bacteriologically. 

Putting aside all samples which were unquestionably "foul brood," 
he attempted to group the remaining ones according to certain 
characteristics observed in a study of the gross appearance of the 
diseased brood. One character which seemed to be emphasized was 
the sour odor emitted by certain samples. On account of this he 
classified this condition as "sour brood." In testing the odor of 
brood dead of the disease, Burri recommends the holding of the nose 

1 Burri, Dr. R., January, 1906. Bakteriologische Untersuchungen tiber die faulbrut und Sauerbrut der 
Bienen. Pp. 39, pi. 1. Vorwort by IT. Kramer. 



BUBEI, JANUARY, 1906. 69 

very near the combs, or, better, the removal of a larva and testing 
it. He calls attention to the fact that "foul brood" (American foul 
brood) and "sour brood" (European foul brood) have probably 
often been confused by bee keepers of little experience and placed 
under one name, "foul brood." 

Another point of difference between "foul brood" and "sour 
brood," as pointed out by Burri, is in relation to the consistency of 
the dead larvae in the two conditions. In "foul brood," he says, a 
uniform ropy mass is all that remains of the decaying larva dead of 
the disease, while in "sour brood" the chitinous covering of the 
decaying larva permits its removal as a whole from the cell. 

Besides the odor and consistency of the dead brood, Burri refers 
to the color as a third characteristic that serves to aid in the differ- 
entiation of "foul brood" and "sour brood." He writes that the 
larvae of "foul brood" are cream colored soon after the development 
of the bacteria has begun, but later are a pale coffee brown, and finally 
a dark brown. In "sour brood," he says, the larvae become discol- 
ored. At first they are a dirty yellow. The dry scales are less black 
than those of "foul brood." 

Burri received samples which were reported to him to be "black 
brood." The older larvae seemed to be affected and the microscopic 
and cultural examinations gave negative results. This strongly sug- 
gests that this is not the condition to which the term "black brood" 
has been referred in America. No conclusion was reached by him 
as to the cause of this trouble. Certain differences were noted by 
Burri between the descriptions by Dadant of the different brood dis- 
eases and his own observations. It is not difficult to understand why 
such differences should exist when one recalls that so many descrip- 
tions of the brood diseases in the past by Americans have been based 
largely upon faulty work. 

Further on in his paper, Burri gives the microscopic findings and 
describes the gross appearance of a few larvae taken from each of the 
eight samples of sour brood which he examined. He mentions in 
"sour brood" the yellowish color of the larvae, the uncapped cells, 
and the presence of rather long rods^ Short rods were also found, 
resembling in morphology Bacterium giintheri. On account of this 
similarity, in recording the presence of this latter species, Burri has 
referred to it as the " guntheri-iovms." These facts concerning the 
gross appearance of the microscopic findings in "sour brood" suggest 
strongly that the condition is the same as the foul brood of Cheshire 
and Cheyne (European foul brood). 

In summing up the results of his study on "sour brood," Burri 
emphasizes two observations: First, that there is a form of disease 
found all over Switzerland which possesses the characters mentioned 
for "sour brood" ; and, second, that in the condition there is a certain 



70 HISTORICAL NOTES ON BEE DISEASES. 

uniformity in the microscopic findings. There were medium-sized 
and small bacterial rods present together with forms resembling in 
morphology' Bacterium giintheri. There was an absence of spores 
and of the corresponding vegetative forms. It was observed that 
one group of bacteria may predominate in some samples and another 
group may predominate in others. Where rods of relatively large 
size were found in brood which in gross appearance resembled sour 
brood, it was supposed that a double or mixed infection of foul brood 
and sour brood was present. This double infection, it was believed, 
occurred very frequently. 

In continuing his bacteriological study of "sour brood" Burn 
encountered a few rather interesting species. Bacillus alvei was pres- 
ent in many samples of "sour brood" examined. From most of the 
samples examined difficulty was encountered in obtaining cultures 
of the microorganism to which he refers as the guniheri-lorms. He 
reports, however, that this difficulty had been overcome and that he 
had obtained pure cultures of this species. He made some compari- 
sons between the cultures of this species and those of Bacterium giln- 
theri which resulted in the conclusion that while there was a certain 
relationship existing between them, the two were not the same. 

Burri sums up the results of his study of "sour brood" as follows: 

1. There is a disease of the brood accompanied by a rapid growth of bacteria, which 
have no direct relation with the bacteria of foul brood. 

2. The larvae attacked are characterized by the following symptoms: (a) More or 
less noticeable sour odor; (6) comparatively pale, dirty yellow color; and (c) a great 
resistance of the chitinous covering which allows the dead larva to be lifted intact 
from the cell as a moist mass. 

3. In microscopic examination the contents of these larvae are characterized by the 
presence of forms resembling sour milk bacteria (giintheri-iorms) beside medium -sized 
and small rods. It is characterized also by the absence of large spore-bearing rods 
and spores. 

4. Pure culture experiments with such bacterial material give proof of a certain 
relationship between the true sour milk bacteria and the giintheri-iorms. The cul- 
tures also show that the medium-sized and small rods are strong acid producers. The 
name "sour brood" is therefore entirely justified. 

With respect to the occurrence of "foul brood" and "sour brood" 
in the same colony one finds the following in Bum's paper: 

In describing each attempt to isolate the sour brood giintheri-iorms the rarely 
expected fact was demonstrated that in a whole series of cases, a growth of colonies of 
Bacillus alvei, the easily cultivated producer of stinking foul brood, was obtained from 
typical sour broody cells instead of the giintheri-iorms desired. The series of cases of 
this kind could be greatly increased. Moreover, in the course of my investigations 
such findings have been repeated such a surprising number of times that I was forced 
to think there must be some close connection between the two diseases. For some 
time I was even inclined to believe that the sour brood bacteria represented only a 
certain stage of development in the foul brood bacteria but gave up this view when 
the morphological question was explained by means of culture experiments. To-day 
it can safely be affirmed that foul brood bacteria, sour brood giintheri-iorms, and the 



BUBBI, JANUARY, 1906. 71 

other types of rods found in sour brood cells are independent organisms, each with its 
own cycle of development. If various pathogenic bacteria are met with in a disease, 
medical men speak of the condition as a mixed infection. It seems that generally in 
sour brood we have to deal with such a mixed infection. As already pointed out, I 
have, occasionally in the microscopic examination, but particularly in the cultural 
tests of the comb material sent in, encountered the mixed infection of sour brood and 
foul brood so regularly, that I scarcely expect to meet with a case of pure sour brood. 
By this I mean a comb with sour brood cells in which at the same time foul brood 
germs are not to be found. This presumption, however, proved not to be true, for the 
specimen from Kaltbrunn must be considered as a case of "pure" sour brood. The 
first specimen from Murten which similarly gave the impression at first of being 
"pure," had to be considered subsequently to be foul brood, for the second specimen 
from the same source showed unquestionably the presence of Bacillus alvei. 

The samples containing dead brood, which Burri studied from May, 
1903, to September, 1905, were grouped under four headings, viz, 
"sour brood," " stinking foul brood," "nonstinking foul brood," and 
"dead brood free from bacteria." 

In summing up Burri's work on "sour brood" the following inter- 
esting facts might be mentioned: 

1. The origin of the term "sour brood" is not definite. 

2. Burri considered three gross characters to be of especial value in 
the diagnosis of "sour brood" — a sour odor, a lack of ropiness of the 
decaying larvae, and a dirty yellow color of the brood recently affected. 

3. In "sour brood" were found a large number of short rods which 
resemble, on microscopic examination, Bacterium giintJieri found in 
sour milk, and with these he found other rods of medium and large size. 

4. When cultures were*made from the larvae dead of "sour brood," 
the gilntheri-forms did not grow as a rule, but in their stead cultures 
of Bacillus alvei appeared sometimes in pure culture. 

5. The cultivation of the guntJieri-forms is reported as having been 
successful. 

6. Burri believed that "sour brood" and the "stinking foul brood" 
are usually found together. This was suggested to him by the 
frequent presence of Bacillus alvei and the guntJieri-forms in the same 
diseased colony. "Sour brood" was reported to have been found 
alone in one instance. 

7. He grouped the samples of comb which contained dead brood 
into four conditions, viz, "sour brood," "stinking foul brood," "non- 
stinking foul brood," and "dead brood free from bacteria." 

8. The true menace to bees he believed to be due to a bacillus 
which is difficult to cultivate. 

We are not inclined to agree with all the views expressed by Burri 
in his work on "sour brood." The condition referred to as "sour 
brood" and "stinking foul brood" are probably but one disease, 
European foul brood; the "non-stinking foul brood" is the same as is 
now known as American foul brood, and the samples which were 
reported as containing no bacteria together with those which were 



72 HISTORICAL NOTES ON BEE DISEASES. 

received labeled " black brood" were in most instances very probably 
the so-called pickled brood. 

This completes for the present the consideration of the investiga- 
tions made by Dr. Burri. His work is executed with much care, and 
his results are correspondingly valuable. For this reason we feel that 
anything which he writes on bee diseases can be recommended to the 
bee keepers for careful study. 

Maassen, June, 1906. 

Several interesting papers on bee diseases have been written by 
Maassen, of Dahlam, Germany. The first paper x to be considered 
is on "foul brood." 

Of the samples received from 119 apiaries, 112 were found upon 
examination to be diseased. Of these 112 samples which were 
declared diseased, Bacillus alvei was found in only 13. 

Maassen fed colonies large amounts of cultures of Bacillus alvei in 
both the vegetative and spore form during the brood-rearing season 
without producing the disease. An attempt was also made to inocu- 
late the brood directly, but negative results were obtained by this 
method (p. 59). The conclusion was therefore drawn that Bacillus 
alvei had not the significance in brood infection that had ordinarily 
been attributed to it. In all cases where Bacillus alvei was not 
found there were other spore-bearing species observed. The pres- 
ence of one species is especially emphasized which offered much diffi- 
culty in cultivation on the' usual media of» the laboratory (p. 60). 
This species he refers to as Bacillus brandenburgiensis. No definite 
proof was obtained of a causal relation between this spore-bearing 
species and the disease. 

It seemed to Maassen at this time that spore-bearing bacteria were 
probably only secondary invaders in this disease condition. He was 
strengthened in his belief by the finding of what he supposed was a 
protozoan to which he gave the name Spirochete apis. In all brood 
affected with the disease he records the presence of this micro- 
structure. It was yet to be determined, he says, whether this last 
finding bore any causal relation to the disease in which it was found. 

In this paper by Maassen the following points are of special 
interest : 

1. Maassen was examining samples of brood which were suspected 
by the bee keepers to be "foul brood." 

2. He does not mention two forms of "foul brood." 

3. He found Bacillus alvei in 13 samples of "foul brood" out of 
112 samples diseased. 

i Maassen, Dr. Albert, June, 1906. Faulbrutseuche der Bienen. Mitteilungen aus der kaiserlichen 
biologischen Anstalt fur Land- und Forstwirtschaft. Heft 2, pp. 28-29. 



MAASSEN, JUNE, 1906. 73 

4. He found in all the samples of foul brood examined, in which 
Bacillus alvei was absent, another species present which offered diffi- 
culties in its cultivation on artificial media and refers to the species 
as Bacillus brandenburgiensis. 

5. He reports this species to be present in some of the samples, 
together with Bacillus alvei. 

6. He used a large amount of the culture of Bacillus alvei in the 
inoculation of healthy bees and did not produce disease. 

7. "Foul brood" was not produced with pure cultures of Bacillus 
brandenburgiensis . 

8. He was inclined to the belief that bacteria are secondary 
invaders in "foul brood." 

9. He believed that this view was strengthened by the finding of a 
microorganism to which he gave the name Spirochete apis. 

10. He reports this microstructure present in all samples of the 
disease which he had examined up to that time. 

Maassen, June, 1906. 

Another paper appeared by Maassen, 1 in which he briefly refers to 
a disease which he says is known to the bee keepers as "stone brood." 

The condition, he says, is characterized by the hard, leathery, 
brittle, odorless, and mummylike masses into which the larvse and 
pupae of bees are transformed with no marked change in their form. 
Accompanying the condition is a higher death rate among the adult 
bees. 

The peculiar change in the brood was attributed to a fungus that 
grows well at a warm temperature, and whose characteristics when 
studied in pure cultures were found to be similar to those of Asper- 
gillus jlavus. The method of transmission of this germ was not 
determined. According to the observations that were made it was 
supposed that bees were very susceptible to the disease. This was 
especially true if the temperature was high or the hive was badly 
ventilated, and it was therefore recommended that these conditions 
be avoided in the treatment of the disease. Maassen expresses the 
belief that "stone brood" has often been referred to by bee keepers 
as "black brood," "new bee disease," "bee pest," and "pickled 
brood." 

We are not familiar with the condition "stone brood," and we are 
not aware of its presence in America. The symptoms given do not 
correspond to those observed in the so-called black brood or in the 
pickled brood that are met with in this country. It is intimated in 
Maassen' s paper that a publication on the mycotic diseases of bees 
was being prepared. 

i Maassen, Dr. Albert, June, 1906. Die Aspergillusmykose der Bienen. Mitteilungen aus der kaiser- 
lichen biologischen Anstalt fur Land- und Forstwirtschaft. Heft 2, pp. 30-31. 



74 HISTORICAL NOTES ON BEE DISEASES. 

Bahr, 1906. 

Another publication by Bahr 1 appeared in 1906, in which he gives 
the results obtained from his further investigations. He reports that 
more than 200 cases of foul brood had been examined. The following 
points are noted in Bahr's paper: 

1. One can not be sure with what disease he was working. 

2. He does not always find Bacillus alvei in foul brood. 

3. With cultures of Bacillus alvei he was not able to produce foul 
brood either by spraying the larvae or by feeding cultures of the 
bacillus. He failed also to produce the disease by using the contents 
of the dead larvae for spraying or as food in sugar sirup. 

4. He suggests that the reason for these negative results may be 
either that Bacillus alvei is not the cause of foul brood or that the 
proper time or manner in which such infection can be produced 
experimentally had not been discovered. 

5. He did not find any other bacillus as a possible cause of the 
disorder. Bacillus alvei was not found in the eggs or in the sexual 
organs of the queen, as had been reported by Cheshire (p. 21), Har- 
rison (p. 49), and others. 

6. He suggests that possibly the cause of the disease is an ultra- 
visible virus and that possibly the disease is transmitted through the 
queen. 

It appears likely that Bahr was working with European foul brood, 
but this is not at present positively known. If he studied American 
foul brood, he must have overlooked the fact that there are numerous 
spores (Bacillus larvse) present in the decaying remains of the larvae 
which do not grow on the artificial media commonly used. In sup- 
port of his theory that the disease is transmitted by the queen he 
says thai he has introduced a queen from a diseased colony into a 
healthy one and produced foul brood as soon as the queen could lay 
the eggs, and that he has introduced queens from healthy colonies 
into apparently doomed ones with the result that the diseased colonies 
quickly recovered. 

These experiments should be repeated for a confirmation of the 
results. If, as is probable, Bahr worked with European foul brood, 
there were probably other factors present which were not accounted 
for. His failure to find Bacillus alvei in all the samples examined 
is interesting, and his failure to produce foul brood with cultures 
of Bacillus alvei repeats the experience of some others. 

i Bahr, L., 1906. Om Aarsagen til Bipesten og dennes Beksempelse. Foredrag holdt ved DBF's Dis- 
kussionsm^de d. 2 Septbr. 1906 i Esbjerg. Ssertryk af Tidsskrift for Biavl. Nr. 17. 



ERNE, NOVEMBER, 1906. 75 

Phillips, October 3, 1906. 

In 1906 a brief circular l was issued by this bureau giving the 
symptoms and treatment of the two brood diseases. This paper is 
of interest at this time only because it was the first occasion for the 
use of the names "American foul brood" and "European foul brood" 
in a publication of the bureau. 

Since the name "black brood" had been, on account of an 
error, applied (p. 45) to the foul brood which Cheshire and Cheyne 
(p. 25) described, the name "black brood" was no longer needed. 
The name "foul brood," however, was being applied by the bee 
keepers (p. 60) to a disease which was clearly different from the foul 
brood described by Cheshire and Cheyne. This latter disease, there- 
fore, needed a name. The laws that were in existence in some of 
the States at that time provided for the inspection of apiaries in 
which foul brood was found. In order that these laws could be inter- 
preted, in accordance with their intent, to cover the brood diseases 
of an infectious nature, the name "foul brood" was retained in the 
names of these two brood diseases. To distinguish the two diseases 
by name, the adjective "European" was selected for the disease 
which had been early creditably studied by a European (p. 29) and 
the adjective "American" was selected for the disease which had 
been studied by an American (p. 62). These names were chosen only 
after consultation with a number of the leading bee keepers in 
America, who agreed that the names were well chosen. 

The words "American" and "European" were not chosen to sug- 
gest a geographical distribution of the two diseases,' as the opinion 
was held that both diseases exist in Europe as well as in America. 
Concerning the selection of these names the facts were emphasized in 
the preface of a paper to be discussed later (p. 76). 

• 
Erne, November, 1906. 

In 1906 Dr. Erne, 2 of Freiburg, Germany, reviewed Burri's work 
on the brood diseases and gave the results of his own investigations. 
Erne, too, obtained negative results in an attempt to produce "foul 
brood" with a culture of Bacillus alvei. This species was not found 
by him in 64 samples of "foul brood" received from different parts 
of Germany. For these reasons he expresses a doubt concerning any 
etiological relation between the species and the disease as found in 
Germany. He found, however, in all samples of the disease a bacte- 
rium which he thought probably was identical with the one which 

1 Phillips, E. P., October 3, 1906. Thebrood diseases of bees. U. S. Department of Agriculture, Bureau 
of Entomology, Circular No. 79. Pp. 5. (Superseded by Farmers' Bulletin 442, U. S. Department of 
Agriculture, "The treatment of bee diseases.") 

2 Erne, Dr. November, 1906. Bakteriologische Untersuchungen fiber die Faulbrut und die Sauer- 
brut der Bienen. Die Europaisehe Bienenzucbt, pp. 148-151. 



76 HISTORICAL NOTES ON BEE DISEASES. 

Bum observed to be difficult of cultivation. As this species was not 
obtained in pure culture, no inoculation experiments were made with 
it. By feeding foul-brood material to ten colonies, however, Erne 
proved that the disease with which he was working was infectious, 
since in every case typical foul brood was produced which contained 
the same bacillus previously observed. 

To make clear his position, Erne summarizes as follows : 

1. Burri has not furnished proof that sour brood is a contagious disease and that the 
bacterium described by him is the cause of the same. 

2. It is not proven that there is more than one foul brood germ. 

3. I consider as the cause of the epidemic foul brood causing the greatest destruction 
at the present time, a bacillus which I have found in all of my investigations, which 
can not be cultivated on the usual media, and which may perhaps be identical with the 
bacillus that Burri found to be difficult of cultivation. 

In Erne's paper the following interesting facts are noted: 

1. He was working probably only with American foul brood. 

2. Erne took exception to the methods used by Burri in the attempt 
to obtain pure cultures of the bacillus which was found difficult of 
cultivation. 

3. He emphasizes the importance of the experimental inoculations 
of healthy colonies in the demonstration of the cause of a disease of 
bees. 

4. He did not find Bacillus alvei in 64 samples of foul brood exam- 
ined from Germany. 

5. He obtained negative results when healthy bees were fed pure 
cultures of Bacillus alvei. 

6. He questioned an etiological relation between Bacillus alvei and 
"foul brood." 

7. He demonstrated the infectiousness of foul-brood material by 
the production of "foul brood' ' in healthy colonies. 

8. He met with a species of bacterium in foul brood which was 
difficult to cultivate on artificial media. 

9. He considered this germ to be the cause of foul brood, although 
the fact was not demonstrated. 

10. Erne did not in his study of "foul-brood" material meet with 
a microorganism corresponding to Spirochete apis. 

While Erne does not devote much time to bee-disease investiga- 
tions, his writings show that considerable care is exercised in his work. 
The bee keepers, therefore, will be profited by reading any papers 
written by this author. 

White, Novembek 6, 1906. 

In 1906 the manuscript mentioned on page 67 was published as a 
bulletin. 1 In the preface the reason for the selection of the names 

i White, G. F., Ph. D. November 6, 1906. The bacteria of the apiary, with special reference to bee 
diseases. U. S. Department of Agriculture, Bureau of Entomology, Technical Series, No. 14. Pp. 50. 



WHITE, NOVEMBER 6, 1906. 77 

" European foul brood" and "American foul brood" for two of the 
infectious diseases of the brood of bees is explained. 

The technique used by the writer of the bulletin in making the 
investigations is given in Part I. In this portion also is discussed 
somewhat the normal flora of the apiary. It was not the intention 
in making this study of the normal flora to give a complete list of the 
bacteria which might be encountered, but to study those species 
which occur most frequently, and to describe them with sufficient 
care to make their identification possible. 

The results of the study indicate that comparatively few bacteria 
are present in healthy colonies, on combs, in honey, in larvae, or on 
adult bees. In the intestine of adult bees, however, there were 
usually found a very large number of individual bacteria, which, as a 
rule, however, represented comparatively few species. One species, 
an anaerobe, is of much interest since it occurs quite constantly and 
in very large numbers. It might be mentioned that the bees that 
did not show this intestinal flora were usually the younger adults. 
A number of fungi and yeasts were also encountered. 

The subject-matter in Part II, "The diseases of bees," is not mate- 
rially unlike that which appeared in earlier publications to which 
references have already been made. The author of the paper under 
consideration had reached no definite conclusion concerning the etio- 
logical relation of Bacillus alvei to European foul brood, the disease 
in which this species is usually found in large numbers. That any 
direct causal relation did exist seemed questionable. 

In American foul brood, Bacillus larvx was found in large numbers 
in the larvse dead of the disease in all the samples examined. Pure 
cultures of the organism had been obtained, but not in a suitable 
form for making inoculation experiments. The author of the paper 
did not feel justified in stating positively that Bacillus larvse is the 
cause of the disease. All that seemed justified was the statement 
that the organism had been found constantly present in the disease. 

The following brief summary was made of the results obtained 
from the study of the bee diseases : 

(1) There are a number of diseased conditions which affect the apiary. 

(2) The disease which seems to cause the most rapid loss to the apiarist is European 
foul brood, in which is found Bacillus alvei — first isolated, studied, and named by 
Cheshire and Cheyne in 1885. 

(3) The distribution of Bacillus alvei in the infected hive is as follows: 

(a) The greatest number of infecting germs are found in the bodies of dead larvae. 
(6) The pollen stored in the cells of the foul-brood combs contains many of these 
infecting organisms. 

(c) The honey stored in brood combs infected with this disease has been found to 
contain a few bacilli of this species. 

(d) The surface of combs, frames, and hives may be contaminated. 

(e) The wings, head, legs, thorax, abdomen, and intestinal contents of adult bees 
were found to be contaminated with Bacillus alvei. 



78 HISTORICAL NOTES ON BEE DISEASES. 

(/) Bacillus alvei may appear in cultures made from the ovary of queens from Euro- 
pean foul-brood colonies, but the presence of this species suggests contamination from 
the body of the queen while the cultures are being made and has no special significance. 

(4) The disease which seems to be most widespread in the United States we have 
called American foul brood, and the organism which has been found constantly present 
in the disease we have called Bacillus larvae. This disorder was thought by many in 
this country and other countries as well to be the foul brood described by Cheshire 
and Cheyne, but such is not the case. 

(5) From the nature of American foul brood it is thought that the organism has a 
similar distribution to that of Bacillus alvei. 

(6) It appears that European foul brood was erroneously called "New York bee 
disease" or "black brood" by Dr. William R. Howard in 1900. 

(7) There is a diseased condition affecting the brood of bees which is being called 
by the bee keepers "pickle brood." No conclusion can be drawn from the investi- 
gation so far as to the cause of the disease. 

(8) Aspergillus pollinis, ascribed by Dr. William R. Howard as the cause of pickle 
brood, has not been found in this investigation and is not believed by the author to 
have any etiological relation to the so-called "pickle brood." 

(9) Palsy or paralysis is a diseased condition of the adult bees. No conclusion can 
yet be drawn as to its cause. 

(10) Formaldehyde gas, as ordinarily used in the apiaries, is insufficient to insure 
complete disinfection. 

Maassen, February, 1907. 

In 1907 Maassen * reported on his work of the preceding year on 
foul brood. Samples were received from 100 apiaries. An exami- 
nation gave evidence of disease in 79 of them. Disease was not 
found in the other 21. "Spirochete apis" was reported in samples 
from 67 apiaries. Accompanying it B. brandenburgiensis was reported 
in 66 cases and B. alvei in one. B. alvei was not found generally in 
the samples from Germany, occurring only in 11 of the cases. 

Among the 100 samples examined there were 2 in which was found 
a species in almost pure cultures which before had been found accom- 
panied by Bacillus alvei. This species Maassen named Streptococcus 
apis. He says that it belongs to the pneumococcus group, being dif- 
ferent from other members of the group by its marked peptonizing 
character. Upon a certain medium he reports that the species could 
be cultivated very easily. In 10 cases in which B. alvei was found 
Streptococcus apis was reported in 8. No conclusive results were 
obtained in his attempts to demonstrate the relation between any of 
the organisms and the disease condition. 

In his report the following points of special interest are noted : 

1 . Maassen did not express any suspicion that two distinct infectious 
diseases might be present in the condition he was studying as foul 
brood. 

2. He reports the presence in samples from 67 apiaries of a micro- 
organism which he had previously named Spirochsete apis, and with 

1 Maassen, Dr. Albert, February, 1907. tiber die sogenannte Faulbrut der Honigbienen. Mitteilungen 
aus der kaiserlichen biologischen Anstalt fiir Land- und Forstwirtschaft. Heft 4, pp. 51-53. 6 lip. 



IMMS, JUNE, 1907. 79 

it he finds associated Bacillus hrandenburgiensis in 66 cases and 
Bacillus alvei in one case. 

3. He found Bacillus alvei in 11 cases of diseased brood. The 
majority of these samples probably were from apiaries affected with 
European foul brood. 

4. He observed and cultivated a species which he named Strepto- 
coccus apis. This species, he states, belongs to the pneumococcus 
group and is easy of cultivation. In 10 samples in which Strepto- 
coccus apis was found Bacillus alvei was found in 8. 

5. He states that he had not reached a final conclusion concerning 
the relation between the microorganisms and the disease encountered. 

Imms, June, 1907. 

The Board of Agriculture and Fisheries of Great Britain requested 
Mr. A. D. Imms, of Christ College, Cambridge, to make a study of 
the cause and nature of a disorder among bees. References to this 
disorder have been made in the last f w years as the Isle of Wight 
disease. Imms * made a report on his work in 1907. 

From this report an idea of the rapid losses which were attributed 
to the disease can be obtained. It is stated that the disease was so 
prevalent that it seemed almost impossible to keep a colony healthy 
for 12 months. Seventy colonies were reduced to 8 in two years. 
One bee keeper lost 20 colonies out of 22. Three other bee keepers 
in the same district lost their entire apiaries, consisting of 12, 8, and 
4 colonies, respectively. Another bee keeper lost over 50 colonies 
and about a dozen other bee keepers had no bees left. 

Imms gives the following in his description of the symptoms of the 
disease : 

The earliest noticeable symptom of the disease is the inability of the affected bees 
to fly more than a few yards without alighting. As the disease progresses, the bees 
can only fly a few feet from the hive and then drop and crawl about aimlessly over 
the ground. They are often to be seen crawling up grass stems, or up the supports 
of the hive, where they remain until they fall back to the earth from sheer weakness, 
and soon afterwards die. In a badly infected stock great numbers of bees are to be 
seen crawling over the ground in front of the hives, frequently massed together in 
little clusters, while others remain on the alighting board. If the hives be opened, 
numbers of diseased individuals will be often met with inside. They are found 
clustered together around the queen and show very little inclination for movement 
until disturbed and are entirely unable to fly. Badly diseased individuals show very 
little inclination for stinging; those that are less severely attacked often sting very 
actively. 

If a badly diseased bee be carefully examined it will be seen to have lost its power 
of flight, and it crawls about with the hinder extremity of the body dragging on the 
ground; frequently it walks about with its wings ''out of joint," the hind wings pro- 
truding obliquely upwards and above the anterior pair. The only other external 

symptom of the disease is seen in the abdomen, which is frequently distended beyond 

i . 

i Imms, A. D., June, 1907. Report on a disease of bees in the Isle of Wight. Journal of the Board of 
Agriculture, Vol. XIV, No. 3, pp. 129-140, 4 figs. 



80 HISTORICAL NOTES ON BEE DISEASES. 

its normal proportions. This distension, however, is not by any means constant, 
and was chiefly noticed in the case of the native bee; in the half-breed with the 
Italian bee, with its longer and slightly more slender abdomen, no unusual distension 
could be observed. 

The disease appears to differ from what is usually termed "bee-paralysis," in that 
the infected individuals do not exhibit the characteristic black and shiny appear- 
ance, and neither I myself, nor any bee keepers who have paid attention to the dis- 
ease, have observed the curious trembling motion of the limbs and body which is 
regarded as a symptom of that disease. 

The disease appears to be entirely confined to the adult bees, the brood remaining 
unaffected. I have conducted a microscopical examination of a large number of 
eggs, larvge at all stages of development, and pupae, and have failed to detect any- 
thing of a pathological nature among the brood. All had the characteristic pearly 
white appearance of healthy specimens although belonging to a badly infected hive. 
The eggs were undergoing development and showed not the slightest trace of discol- 
oration or shriveling, the larvae were healthy in every way and were coiled up in 
their normal attitude, and nothing wrong could be detected with the pupae or the 
newly hatched bees. 

In describing the " Nature of the disease" Imms writes in part as 
follows : 

The disease is eminently one of the digestive system and might be described as 
being a condition of enlargement of the hind intestine. Over 150 diseased bees 
have now been examined and all have been found to exhibit the same symptoms. 

The author states that the bacteriological work on the disease was 
in progress. The work which had already been done demonstrated 
the presence of a large number of bacterial rods. No conclusion was 
reached as to the cause of the disease, nor had any remedy been found 
in the treatment that was successful in the hands of all bee keepers. 

Some of the more important points in the paper might be summa- 
rized as follows: 

1. The disease, so far as was determined, was of recent origin. 

2. The disorder described seemed to be very rapidly fatal to adult 
bees. The brood seemed to be unaffected. 

3. To Imms the trouble seemed to be neither dysentery nor the 
so-called paralysis. 

4. No conclusion was reached as to the cause of the disorder. 

5. No treatment was demonstrated to be successful. 

White, July 29, 1907. 

On July 29, 1907, there was issued a circular x briefly describing 
some experiments which demonstrated for the first time the cause of 
American foul brood. Although spores had been observed in very 
large numbers in the larvae dead of this disease, no satisfactory 
medium had yet been devised by which pure cultures could be 
obtained that were suitable for purposes of experimental inoculations. 

i White, G. Franklin, July 29, 1907. «The cause of American foul brood. U. S. Department of Agri- 
culture, Bureau of Entomology, Circular No. 94. Pp. 4. 



WHITE, JULY 29, 1907. 81 

The way by which this difficulty is overcome is reported in the pub- 
lication under consideration. Young pupae were used in making the 
medium. These were picked from a comb containing healthy brood, 
crushed, strained through cheesecloth, and then diluted by adding 
water equal to from 20 to 50 times the volume of the crushed brood 
used. This solution was then passed through ordinary filter paper 
and subsequently through a Berkefeld filter. In this way a sterile 
filtrate was obtained. About 2 c. c. of the sterile filtrate was then 
added by means of a sterile pipette to liquefied agar which had been 
cooled to 45° or 50° C. If pure cultures were desired; agar tubes 
thus prepared were inoculated with a small amount of diseased brood 
and plates were poured. If, however, culture growth was desired 
for the inoculation of bees or experimental animals, it was obtained 
from these specially prepared agar tubes by first inclining them 
and then securing the growth by inoculating the surface of the 
inclined agar with a pure culture of Bacillus larvse obtained from the 
plates. At no time was this special medium to reach a high temper- 
ature. 

Two colonies were now fed the scales of American foul brood, 
suspended in sirup. American foul brood resulted from these inoc- 
ulations with symptoms the same as are found in an apiary in which 
the disease appeared through the natural means of infection. 
Similar results were reported by Erne (p. 76). These experiments 
were sufficient to prove that American foul brood can be produced 
experimentally by feeding; also, that the scales of the disease 
contained the virus. 

Having demonstrated the fact that American foul brood can be 
produced by feeding and having obtained pure cultures of Bacillus 
larvse, in suitable form for inoculation purposes, the next step to be 
taken, very naturally, was to inoculate healthy colonies with pure 
cultures of Bacillus larvse. This was now done, and as a result of 
such inoculations American foul brood was produced with symptoms 
identical with those produced when the scales were used in feeding. 
The decaying brood in the disease thus produced contained the large 
number of spores that are always found in brood dead of this disease, 
and from the diseased material pure cultures of Bacillus larvse were 
obtained. 

The results obtained from these experiments in which pure cul- 
tures of Bacillus larvse were used in making the inoculations justified 
for the first time the statement that American foul brood was caused 
by a specific microorganism. 

It seemed to the author of the circular that probably the species 
which had given different workers considerable difficulty in culti- 
vation, in many cases at least, was nothing other than Bacillus 
13140°— Bull. 98—12 6 



82 HISTORICAL NOTES ON BEE DISEASES. 

larvse. The " microorganism" named Spirochete apis by Maassen 
(p. 72) was shown to be giant whips which have their origin in the 
growth of Bacillus larvx. 

Phillips, December 31, 1907. 

In connection with the study of American foul brood it was noticed 
that the scales formed by the drying down of the dead larvse are not 
destroyed if the comb becomes infested with either of the two wax 
moths. These observations were recorded in a publication 1 of this 
bureau. Sometimes it is desirable to have the dried scales of Amer- 
ican foul brood in large quantities. These can be easily obtained 
free from the comb by allowing a well dried and badly diseased 
sample to become infested with wax moths. 

Maassen, 1908. 

Another paper 2 by Maassen appeared in 1908. In his former publi- 
cations this author has dealt with only one form of foul brood. In this 
paper, however, he states that two forms of the disease have been 
known for many years, a "mild" form and a " virulent" one. 

Maassen's description of the gross appearance of the brood affected 
with the "mild" form is similar to that given by Dzierzon (p. 18) and 
others. The disease therefore is quite probably European foul brood. 
This view is further strengthened by the bacteriological examinations 
which he reports. His description of the "virulent" form is also 
similar to that given by Dzierzon (p. 18) and others. The condition 
is most likely, therefore, American foul brood. 

Following the discussion of these two forms of "foul brood " Maassen 
discusses the etiology of "foul brood." He expresses the belief that 
foul brood is a disease of the digestive apparatus of the larvae and can 
be produced by various causes. As producers of "foul brood" 
Bacillus alvei, Streptococcus apis, and Bacillus brandenburgiensis are 
mentioned by him. Besides these three species he reports the pres- 
ence in the diseased brood of a species of yeast and spore-bearing 
bacilli. Bacillus alvei and Streptococcus apis are reported to have been 
found in both forms of foul brood, while Bacillus brandenburgiensis was 
found in only one of them. 

In that form of the disease in which uncapped brood seemed mostly 
to be affected, Maassen reports the presence of Bacillus alvei in 51 
samples out of the 53 examined. When Bacillus alvei predominated 
in the sample, he interpreted the odor as being more "sweat-like" in 
character than when Streptococcus apis was in predominance; and 

1 Phillips, E. F. December 31, 1907. Wax moths and American foul brood. U. S. Department of Agri- 
culture, Bureau of Entomology, Bulletin No. 75, Part II. Pp. 19-22. 

> Maassen, Dr. Albert, 1908. Zur Atiologie der sogenannten Faulbrut der Honigbienen. Arbeiten aus 
der kaiserlichen biologiscben Anstalt fur Land- und Forstwirtschaft. Bd. VI, Heft I, pp. 53-70. 2 pis. 



MAASSEN, 1908. • 83 



when the latter species predominated the odor was likened to that of 
sour paste. In samples from two apiaries Maassen failed to find 
Bacillus alvei, but found Streptococcus apis in large numbers. The 
two cases in which Bacillus alvei was absent were suspected of being 
the sour brood referred to by Burri (p. 68). Maassen was inclined to 
believe that the latter condition is more widespread in Switzerland 
than in Germany. In 41 samples of the 51 containing Bacillus alvei, 
the species was accompanied by Streptococcus apis. The relative 
number of Bacillus alvei and Streptococcus apis varied. 

The " guntTieri-foims" mentioned in Burri's paper (p. 69) are very 
probably the species to which the name Streptococcus apis Maassen 
has been applied. Maassen expresses a similar belief. The following 
description of Streptococcus apis is an abbreviation of the one by 
Maassen. 

Occurrence. — This species is found in "foul brood/' occurring most 
frequently in that form in which the larvas when attacked are 
uncapped. 

Morphology. — In form it is not perfectly spherical but is a lancet- 
like, pointed coccus that appears as either a Diplococcus or a Strep- 
tococcus in the body of the larvae as well as in artificial media. A 
capsule is present. 

Gram's stain. — The organism is not decolorized by gram's method. 

Oxygen requirements. — It grows aerobically as well as anaerobically. 

Bouillon. — The medium becomes at first turbid, and later a deposit 
forms at the bottom of the tube. Reaction is but little changed. 

Glucose, lactose, saccharose, galactose, levulose, and mannite oouil- 
lons. — Increased growth takes place in these bouillons with the for- 
mation of acid. 

Agar slant. — A thin iridescent growth takes place. The conden- 
sation water is clouded with a sediment present. 

Blood serum. — There is a perceptible growth. The colonies are 
drop like. No liquefaction of the medium takes place. 

Potato. — The organism grows well on this medium. 

Milk. — Growth takes place rapidly. After 24 hours the casein is 
coagulated and later some of the coagulum peptonizes. 

Gelatin. — After about 40 hours at 20° C. a whitish-gray growth is 
observed with a beginning liquefaction of the medium. 

Indol. — Indol is not formed. 

Nitrates. — Nitrates remain unchanged. 

Disinfectants. — This species proved very resistant to drying. After 
three-fourths of a year of drying the organism was not dead. 

Burri (p. 70) met with some difficulty in the cultivation of the 
species to which he referred as the giintheri-f oims. In a few cases, 
Maassen apparently had some difficulty also with his Streptococcus 
apis, but in most cases no difficulty was encountered. The difficulty, 



84 HISTORICAL NOTES ON BEE DISEASES. 

Maassen says, was obviously due to an acid which was present. He 
likened the condition to that obtained in cultures in those artificial 
media hi which a sugar is present. Maassen suggests that the death 
of Streptococcus apis under these conditions is not without signifi- 
cance if this organism is the cause of the disease. 

The feeding of pure cultures of Streptococcus apis to healthy colo- 
nies gave negative results. He reports that negative results were 
obtained also when healthy colonies were fed larvae containing the 
cocci with no Bacillus alvei present. When similar larvae, however, 
were fed to healthy bees together with a suspension of the spores of 
Bacillus alvei he reports that the disease was produced. 

Having considered the etiology of the "mild" form of foul brood 
(European foul brood), Maassen took up for consideration the cause 
of the so-called "virulent" form of the disease (American foul brood). 
This latter disease, he says, is far more widespread in Germany than 
is the former. From 347 samples of diseased brood examined in &ve 
years, 294, almost 90 per cent, were affected with the "virulent" 
form of the disease. In this form he usually found Bacillus branden- 
burgiensis. This species was so named by him because his first 
experience with it was in a sample from the Province of Branden- 
burg, Prussia. Maassen describes the morphology and cultural char- 
acters of Bacillus brandenburgiensis. He says that this species is 
the cause of the foul brood most commonly found in Germany. 

Maassen also says that he found spirochaete-like forms (p. 73) in 
the unstained decaying "foul-brood" mass. He considers them a 
good diagnostic agent in the virulent form of the disease. He says 
further that in the progress of his investigations he found Spirochete 
apis to be nothing more than tufts of the flagella of Bacillus branden- 
burgiensis (p. 82). He also says that after great difficulty two 
media were found on which Bacillus brandenburgiensis grew well. 
One was agar made from bee larvae (p. 62), and the other was 
agar made from the brains of calf or of pig. Maassen reports that 
he has produced disease by feeding cultures of Bacillus branden- 
burgiensis. Each colony fed received the cultures from 10 to 20 
tubes. When considerable culture was fed the disease appeared in 
from 6 to 10 days after the feeding of the colony. He states that the 
disease is present in America, and that a bacillus has been found in 
it which has been named Bacillus larvse. 

Maassen has therefore confirmed most of the facts stated in the 
paper (p. 80) which was received by him at least four months before 
his was published. 

The following is a brief summary of Maassen's paper: 

1. He mentions that he has encountered in his studies two forms 
of foul brood. These were described by Dzierzon and others. 



WHITE, DECEMBER 26, 1908. 85 

2. The form which seems to be European foul brood he refers to 
as the "mild" form; and the other one, which seems to be American 
foul brood, he refers to as the " virulent" form. 

3. In the "mild" form he finds Bacillus alvei and Streptococcus 
apis, together with a few other species. 

4. In two instances he did not find Bacillus alvei present, but did 
find Streptococcus apis. This condition he believes to be the "sour 
brood" of Burri. 

5. In a few cases only he reports difficulty in obtaining cultures of 
Streptococcus apis on artificial media. 

6. In the disease (American foul brood) which is most common in 
Germany, Maassen finds a species which he calls Bacillus branden- 
burgiensis. 

7. In this disease he also finds Bacillus alvei generally associated 
with Bacillus brandenburgiensis . 

8. In a few samples he found Streptococcus apis accompanying 
Bacillus brandenburgiensis. 

9. In his experimental inoculations, he obtained positive results 
when Bacillus brandenburgiensis in either the vegetative or spore 
form was fed to a healthy colony. 

10. He obtained negative results when healthy colonies were fed 
cultures of Streptococcus apis. 

11. He failed to produce disease by feeding to the healthy colonies 
dead brood containing Streptococcus apis but no Bacillus alvei. 

12. He reports positive results when the spores of Bacillus alvei 
were fed together with dead brood containing Streptococcus apis. 

Maassen, September, 1908. 

Maassen 1 published another paper in 1908. He reviews briefly 
the history of the study of foul brood. An attempt was made to 
learn of the distribution of the diseases in Germany. For this pur- 
pose letters were sent to bee keepers in various parts of the country, 
making inquiry into the disease conditions of the apiaries. Answers 
were received from two States. He obtained data, however, from 
other sources which caused him to believe that foul brood is frequent 
in almost all of the German States. A review is then made of his 
own investigations relating to foul brood. 

White, December 26, 1908. 

The object of a paper 2 read before the National Bee Keepers' 
Association on October 14, 1908, was to direct the attention of bee 

1 Maassen, Dr. Albert, September, 1908. Uber die unter dem Namen "Faulbrut" bekannten seuchen- 
haften Braterkrankungen der Honigbiene. Mitteilungen aus der kaiserlichen biologischen Anstalt fur 
Land- und Forstwirtschaft. Heft 7. Pp. 24. 4 Tafeln. July, 1909. 2 Auflage. Pp. 31. 4 Tafeln. 

2 White, G. Franklin, Dec. 26, 1908. The relation of the etiology (cause) of bee diseases to the treatment. 
U. S. Department of Agriculture, Bureau of Entomology. Bulletin No. 75, Part IV, pp. 33-42. Reprinted. 
Annual Report of the National Bee Keepers' Association for 1908. Pp. 60-65. U. S. A. 



86 HISTORICAL NOTES ON BEE DISEASES. 

keepers to the important relation which exists between the etiology 
of a disease and its rational treatment. 

The author at first deemed it advisable to direct the attention of 
his hearers to a consideration of the nature of disease. A brief dis- 
cussion is then given of the etiology of diseases, illustrating the state- 
ments made mainly by citing phenomena observed in bee diseases. 
In discussing the etiology, the usual division into predisposing and 
exciting causes is made. Of the predisposing causes of diseases it 
seemed well to mention age, sex, heredity, race, climate, and pre- 
existing disease, inasmuch as these factors may be active in one or 
more of the diseases of bees. Of the exciting causes of disease, food 
and microorganisms are the only ones mentioned, since food, bacteria, 
protozoa, and fungi have been thought by one writer or another to 
be the direct exciting cause of bee diseases. A brief reference is 
then made to the nature of bacteria, protozoa, and fungi. 

Mention is made in the paper of the fact that a microstructure had 
been encountered in the investigations of European foul brood which 
had failed to grow on artificial media. This was referred to as 
"Bacillus Y." Some hope was entertained that it might sometime 
be proved to be the exciting cause of the disease. The great resistance 
exhibited by the spores of Bacillus larvx toward disinfectants was 
emphasized by citing some preliminary experiments. 

The following are some of the facts to which the attention of the 
bee keepers was directed : 

1 . Disease is nothing more than a departure from a state of health. 

2. The departure is the result of some cause. 

3. The cause is, as a rule, a combination of factors which constitute 
what is known as the etiology. Age, sex, race, and climate seem to 
figure as predisposing factors in bee diseases. Bacteria, protozoa, 
and fungi have all been studied as probable exciting causes. Bac- 
teria are the only kind of a microorganism that has been proven to 
be the cause of a bee disease. 

4. Comparatively little is known of the etiology of bee diseases — 
a statement which, as one becomes familiar with the diseases of other 
animals and man, is found to be true for them also. 

5. The exciting cause of but one bee disease is positively known. 

6. A rather interesting microstructure was encountered in Euro- 
pean foul brood which had refused to grow when sown upon artifi- 
cial media. This is referred to as " Bacillus Y." 

7. A treatment, either preventive or curative, can best be devised 
only after the cause is determined. 

8. Before treating a disease, a diagnosis is advisable. This can 
most accurately be done by knowing the cause and finding it in the 
diseased body. 



MALDEN, FEBRUARY, 1909. 87 

9. The conclusion drawn is that in a knowledge of the causes of 
bee diseases lies hope for their control. 

Malden, February, 1909. 

In 1909 Dr. Maiden, of Cambridge, England, made a report ! 
on his investigations of a disease which appeared on the Isle of 
Wight. A paper by Imms (p. 79) discussing this disorder has already 
been considered. 

Maiden went to the island in May, 1908, and by interviewing the 
bee keepers and inspecting colonies found that the disease had appar- 
ently quite died out. The disease had been seen, however, in March 
and early April of that year. After a short period of apparently 
complete absence the disease again appeared about the middle of 
June, 1908. 

Maiden states that as a rule the disease causes greater losses during 
the summer than in winter. The reverse, however, has been noted 
at times. May and June are according to most observers the months 
during which the disease is usually most rapidly fatal. Infected 
colonies are not always destroyed. They may recover but are sub- 
ject to a later attack by the disease. 

Maiden's investigations into the cause of the disease include a 
study of the gross and microscopical anatomy of the diseased bee, 
together with a bacteriological study of it. In his bacteriological 
study one species was encountered to which, on account of its resem- 
blance to Bacillus pestis, the supposed cause of bubonic plague, he 
gave the name Bacillus pestiformis apis. The morphology, cul- 
tural characters, and pathogenic properties of this bacillus are 
given as follows by Maiden : 

It is an aerobic, non-motile, Gram negative, non-acid-fast, short, broad bacillus, 
varying in its morphological appearances upon different me^ia. No flagella could be 
demonstrated. On agar it grows fairly well, forming in twenty-four hours medium- 
sized (largest 0.1 cm. in diameter), round, white or slightly yellowish, smooth, glis- 
tening, flattened, dome-shaped colonies. On further growth the colonies do not 
increase much in size, and unless very thickly sown they show little tendency to 
coalesce. After twenty-four hours' growth the bacilli are of medium length (1-1. 5/*), 
broad, and with distinctly rounded ends. Many of them are distinctly oval. They 
have a tendency to stain better at the ends than in the middle (polar staining). Occa- 
sionally the lightly staining central portion appears as a distinct band, especially 
when the organism is lightly stained. After seven days' growth very little general 
change is noticed, though a few large involution forms make their appearance. On 
gelatin growth takes place rapidly in the form of colonies, resembling those produced 
on agar. The organisms are more rounded than on agar, being distinctly oval in shape, 
and polar staining is not so marked. On potato a considerable raised cream coloured 
growth is produced in twenty-four hours at 37° C, which continues to spread. The 
bacilli are larger than when grown on agar, but the light central band is not quite so 

1 Maiden, Walter, M. A., M. D., February, 1909. Further report on a disease of bees in the Isle of Wight. 
Journal of the Board of Agriculture, Vol. XV, No. 11, pp. 809-825. 



88 HISTORICAL NOTES ON BEE DISEASES. 

well defined. When stained by Neisser's method, a few show polar bodies (meta- 
chromatic granules). Involution forms, many of which grow to a large size, appear 
rapidly, and are very abundant after forty-eight hours' growth. In broth at 37° C. a 
cloudy growth is first formed, but later the medium becomes clearer, and a consid- 
erable yellowish, flocculent deposit is produced. A surface film is usually seen after 
a few days' growth, and may be very marked. If the tube is shaken, the film sinks, 
or is broken up, but another forms. The bacilli resemble those found on gelatin cul- 
tures. No acid or gas is produced in media containing glucose, lactose, saccharose, 
dulcite, mannite, maltose, dextrin, or glycerine. 

Pathogenic Properties. — A single infection experiment was made with a culture of 
this bacillus. A healthy stock of bees was placed in a hive in a green-house. After a 
few days all the openings were closed with muslin, and the bees fed on syrup. When 
the bees had become accustomed to this treatment, broth cultures of the bacillus were 
mixed with the syrup. Within a few days considerable numbers had died, and speci- 
mens of apparently diseased bees showed the bacilli in their chyle stomachs, which also 
showed the fragile condition found in naturally infected bees. Distention of the colon 
could not be taken as a diagnostic point, as this condition was found to be present in 
healthy specimens of this stock taken from the hive before the experiment was started. 
The majority of the bees showed no signs of disease a week after feeding was com- 
menced. 

The results of the anatomical and bacteriological studies of this 
disease by Maiden are clearly set forth in the following quotation 
from his paper: 

Anatomically the majority of diseased bees show great distention of the colon, and 
a fragile condition of the chyle stomach. In many obtained from diseased stocks, 
and apparently suffering from the disease, distention of the colon is absent. All the 
organs, except those just mentioned, are normal. Healthy bees confined to their 
hives for a few days very closely resemble diseased bees in regard to the condition 
of their intestinal canals. It is impossible, therefore, both from the clinical and 
anatomical points of view, to diagnose whether any given bee is suffering from the 
disease or not. 

Histologically the chyle stomach appears to be the only organ affected, and bac- 
teriologically plague-like bacilli were frequently encountered in it, in some cases 
apparently within the epithelial cells. These bacilli were not found either in the 
brood of diseased hives or in the chyle stomachs of healthy bees. For these reasons 
I am inclined to regard these organisms as the cause of the disease. I am, however, 
well aware that I have not fully established their relationship to the disease, since 
I have not been able to demonstrate them in every case either microscopically or by 
culture, or to find, except in very advanced cases, any very definite lesions con- 
stantly associated with their presence. I feel that my inability to discover any 
means of cultivating the organism with certainty even from chyle stomachs, in which 
it was present in abundance as shown by microscopical preparations, constitutes the 
most serious difficulty in establishing its relationship to the disease. By their mor- 
phology alone, few pathogenic bacteria can be recognized, since morphologically 
indistinguishable, but non-pathogenic, organisms are frequently encountered. Con- 
sequently, until some satisfactory cultivation methods have been discovered, the 
bacteriological diagnosis of this organism must in most cases remain in doubt, for 
03 ;anisms simulating it in morphology probably exist. A 

Concerning this disease and its cause the following points are to 
be emphasized: 

1. Maiden found the disease which Imms reported still present on 
the Isle of Wight. 



ZANDER, AUGUST, 1909. 89 

2. The evidence obtained indicates that the disease is infectious. 

3. An organism was encountered in a number of diseased bees, to 
which Maiden gave the name Bacillus pestiformis apis. 

4. This organism was not proven by Maiden to be the cause of 

the disease. 

Zander, August, 1909. 

In 1909, Dr. Zander, at Erlangen, Germany, wrote an interesting 
paper * concerning the cause of a disease affecting the adult honey 
bee„ 

From his studies Zander was led to believe that there are two 
forms of dysentery. One form he considers to be noninfectious and 
comparatively harmless. The cause of this form is attributed to 
various conditions, such as disturbance of the colony, queenlessness, 
improper winter stores, deficient opportunity for a cleansing flight, 
etc. A second form of dysentery Zander refers to as the malignant 
form. In referring to the virulence of this form Zander says that it 
has all the characteristics of an infectious disease, destroying more 
colonies in one spring in the neighborhood of Erlangen than foul 
brood had during the entire preceding year in the whole State of 
Bavaria. 

During his investigations in 1907 Zander found in the mid-gut of 
diseased bees a protozoan to which the name Nosema apis was given. 
This portion of the intestine of all the bees which died of the " viru- 
lent " form of dysentery was found to be milk-white and completely 
filled with Nosema spores. Queens from dysenteric colonies were 
examined and found also to be infected with the protozoan. No 
drones were found infected. This was supposed to be due to the fact 
that there are no drones during the active dysenteric season. The 
excrement from the bees also contained numerous spores. 

Zander expresses the belief that the transmission of the disease is 
made possible by the deposit of excrement on the frames and walls of 
the hive, which takes place when no opportunity is afforded the bees 
for a cleansing flight. The mutual feeding practiced by bees hastens, 
it is suggested, the spread of the infection. The bees are supposed 
to be subjected to further infection from without on account of the 
spores that are spread about through the medium of the excreta of the 
flying bees. Robbing also is given as a fruitful means of transmission. 
The use of contaminated combs from apiaries in which the infection 
is present is also thought to be a means for the spread of the disease. 

The prognosis is supposed to depend somewhat upon conditions. 
Long, hard winters are given as a cause of very heavy losses with tlas 
disease. If, on the other hand, the spring is warm with a good flow 

1 Zander, Dr. Enoch, August, 1909. Tierische Parasiten als Krankheitserreger bei der Biene. Munche- 
ner Bienenzeitung, Heft 9. Pp. 11. 



90 HISTORICAL NOTES ON BEE DISEASES. 

and the old bees are rapidly replaced by young healthy ones, the 
young bees remain healthy unless a second infection takes place. It 
is suggested that if this second infection takes place it asserts its pres- 
ence about four weeks after the first outbreak. It is then commonly 
thought by the bee keeper to be a different disease, the one to which 
the name "May disease" is sometimes applied. In the so-called 
"June disease" Zander reports the presence of infection with Nosema 
apis also. 

Zander performed some inoculation experiments for the purpose of 
demonstrating the relation of Nosema apis to the "virulent" type 
of dysentery. He describes one in which infected material was fed in 
honey to a colony free from disease. The excrement from bees affected 
with dysentery, together with bees so affected, was ground and added 
to diluted honey. The mixture was filtered and put into two combs, 
and the combs were placed into a queen-right colony, which had been 
examined and found to be free from disease. Three days later the 
bees began to die with all the symptoms of "May" and "June" 
disease. Many dead and dying bees were found in the yard in the 
direction of flight of the bees. A microscopic examination demon- 
strated the presence of Nosema apis in these bees. After eight days 
the mid-gut of most of the diseased bees was milk-white. The colony 
became weaker and weaker, and at the end of a month only a hand- 
ful of bees remained. 

Zander concludes from his work that Nosema apis is the exciting 
cause of the infectious form of dysentery. 

The following is a brief summary of Zander's first paper on Nosema 
apis and the disease with which he found it associated: 

1. Zander discovered a protozoan that attacks the epithelial cells 
of the mid-gut of the adult honey bee. To this protozoan was given 
the name Nosema apis. 

2. He discusses dysentery of bees under two forms — a mild form 
and a virulent one. 

3. He believes the mild form to be noninfectious and probably due 
to a number of different causes; the infectious or virulent form he 
believes to be due to Nosema apis. 

4. He is inclined to believe that this infectious form is the same 
disorder as the one to which "May disease" and "June disease" has 
frequently been applied. 

5. It should be noted that Zander does not claim to be working with 
a new disease, but is simply seeking to determine the cause of d3 r sen- 
tery — a disease with which most bee keepers have had experience. 



HISTORICAL NOTES ON BEE DISEASES. 91 

Maassen, March, 1910. 

Another paper * by Maassen appeared in 1910. 

At this time the content of the intestinal tract of bees taken from 
colonies affected with different brood diseases was made the subject 
of study. 

When bees were examined that were taken from colonies suffer- 
ing from "sour brood/' Maassen reports the presence of Streptococcus 
apis. This species thrives well, he says, in the intestine, and its 
power to grow upon artificial media is not lost (p. 84). Likewise, he 
reports that the spores of Bacillus alvei will develop and the organism 
grow in the intestine of adult bees. Confined bees, it is stated, 
showed the presence of these two species for weeks in the intestine. 

In the case of American foul brood, Maassen reports that the 
spores of Bacillus brandenburgiensis do not germinate in the intestine 
of the adult bee, nor do the vegetative forms multiply there. He 
reports that after a few days a noticeable decrease is to be observed 
in the number of spores present. These observations caused Maassen 
to caution those treating bee diseases against the probability of 
infection from these germ carriers. 

The paper also contains a report on the samples received for 
diagnosis. Material was received from 85 apiaries. When exam- 
ined, 66 of the samples gave evidence that disease was present. 
Forty-five are reported as American foul brood, one as a mixed 
infection of American foul brood and European foul brood, 10 as 
European foul brood, and 10 as a mixed infection of European foul 
brood and sour brood. 

Here the following points are to be noted : 

1. Maassen reports that Bacillus alvei is found in the intestine 
of adult bees taken from a colony affected with European foul brood 
and that this species multiplies in this locality. 

2. He reports that Streptococcus apis is found in the intestine 
of bees that are taken from colonies affected with sour brood and 
that this species also multiplies in this locality. 

3. He reports that the spores of Bacillus brandenburgiensis do not 
increase in the intestine of the adult bee. 

4. These germ carriers, Maassen suggests, must not be overlooked 
in devising methods of treatment. 

1 Maassen, Albert, March, 1910. Untersuchungen iiber die Epidemiologic der sogenannten Faulbrut 
der Bienen. Mitteilungen aus der kaiserlichen biologischen Anstalt fur Land- und Forstwirtschaft, Heft 
10, pp. 37-39. 



92 HISTORICAL NOTES ON BEE DISEASES. 

Maassen and Nithack, March, 1910 

Simultaneously with the paper just considered there was pub- 
lished a paper * on bee dysentery by Maassen and Nithack. Dead 
adult bees from entirely isolated localities were received and exam- 
ined. There was a history of supposed poisoning accompanying the 
bees. No cause for their death, however, could be found. It is 
recorded that no Nosema apis was found. 

The first dysentery observed by these men was in two colonies 
taken from different apiaries. One was a queenless two-frame 
nucleus and the other a queen-right colony of six frames. These 
two colonies were transferred to wire cages. After about three 
weeks symptoms of dysentery were observed. At the beginning of 
the spotting Nosema apis was not found in the excrement, but could 
be demonstrated in the mid-gut. Several days later, when the 
intestine showed the appearance described by Zander, the parasite 
was found in the intestine. 

These findings caused Maassen and Mthack to confine in wire 
cages a series of small queenless colonies. These cages were kept in 
a room whose temperature ranged from 14° to 16° C. The bees were 
obtained from different sources, and all chances of becoming infected 
from food, hives, or combs subsequent to being taken into the room 
were excluded. The results obtained from this experiment were 
similar to those of the preceding one. Other experiments somewhat 
similar were performed. 

These men report that in many colonies in which no visible signs 
of dysentery were present there were found bees containing Nosema 
apis. They believe that among bees this protozoan is widely dis- 
tributed. Up to the time of their writing they had not failed to find 
it in colonies that were suffering from dysentery. 

Malden, June, 1910. 

In 1910 Maiden in a paper 2 gave a good brief review of the status 
of the present knowledge of bee diseases. He gives some further 
observations concerning the Isle of Wight disease. Referring to 
Bacillus pestiformis apis (p. 87) he writes in part as follows: 

This organism may frequently be found to have penetrated between the cells of 
the lining membrane of the chyle stomach and to be present in large numbers in the 
loosened tissue behind the secreting cells. It has been found present in about 60 
per cent, of all the bees affected with this disease which have been examined. * * * 
It appears highly probable that this organism is the cause of the disease, but up to the 
present time no infection experiments have been successful in producing the com- 
plaint in healthy stocks, so that its relation to the disease cannot be said to be proved. 

1 Maassen und Nithack, March, 1910. Uber die Ruhr der Bienen. Mitteilungen aus der kaiserlichen 
biologischen Anstalt fur Land- und Forstwirtschaft, Heft 10, pp. 39-42. 

2 Maiden, Walter, M. A., M. D., June, 1910. Diseases of bees. Reprinted from The Journal of Economic 
Biology, Vol. V, Pt. 2. Pp. 41-48. 



THE DIFFERENT DISEASES THAT ATTACK BEES. 93 

Maiden reports that the disease had within the previous two years 
spread from the Isle of Wight to the mainland (England). There 
seems to be evidence that the virulence of the disease is less than 
when first observed on the Isle of Wight. 

Zander, 1910. 

Zander in 1910 in a publication * gives a good brief review of the 
work that has been done on the cause of the brood diseases. The 
disease in which Streptococcus apis is found Zander refers to as 
"sauerbrut"; the disease which he refers to as "faulbrut," we call 
American foul brood; and we diagnose as European foul brood what 
he refers to as "brutpest." 

Zander, 1911. 

In 1911 Zander writes 2 of the diseases and enemies of the adult 
bees. The morphology, life history, and distribution of Nosema apis 
(p. 89) had been the subject of further study by him and in this pub- 
lication he gives the results of his work. 

A BRIEF CHRONOLOGICAL SUMMARY OF THE WORK ON THE 

CAUSES OF BEE DISEASES. 

THE DIFFERENT DISEASES THAT ATTACK BEES. 

That bees suffer from disease is recorded in the writings prior 
to the Christian era. It is not known, however, which diseases are 
referred to. 

Schirach (p. 13) in 1771 classified the diseases of bees. In his 
classification he mentions, among other diseases, dysentery and foul 
brood. 

Just when and by whom it was first recognized that foul brood was 
of two forms is not known. It would seem that Schirach, in 1771, 
observed that foul brood was not always the same. One finds that 
Leuckhart (p. 14) in 1860 and Molitor-Mtihlfeld (p. 14) and Preuss 
(p. 15) in 1868, all indicated by their writings that they considered 
foul brood to be of more than one form. 

Dzierzon (p. 18), in his "Rational Beekeeping" in 1882, describes 
two forms of foul brood. The descriptions of the two forms agree 
very closely with those of European foul brood and American foul 
brood. 

Cheshire (p. 19) began to write early in the year 1884 of two forms 
of foul brood, but before the close of the year he (p. 22) declared that 
there was only one form. 

i Zander, Dr. Enoch, 1910. Die Faulbrut und ihre Bekampfung. Part I. Handbuch der Bienen- 
kunde in Einzeldarstellungen. Mit 4 Tafeln und 8 Abbildungen nach Originalen des Verfassers. Pp. 31. 

2 Zander, Dr. Enoch, 1911. Krankheiten und Schadlinge der erwachsenen Bienen. Part II. Hand- 
buch der Bienenkunde in Einzeldarstellungen. Mit 8 Tafeln und 13 Abbildungen grosstenteils nach 
Originalen des Verfassers. Pp. 40. 



94 HISTORICAL NOTES ON BEE DISEASES. 

During the following decade there continued to be different opinions 
entertained as to the classification of the infectious brood diseases. 

Many bee keepers were convinced from their experience with the 
diseases of the brood that there existed two distinct infectious dis- 
orders (p. 60). By a more careful study of these diseases it has been 
shown positively that the brood is attacked by more than one infec- 
tious disease. 

These diseases as understood by the writers of this bulletin are 
briefly discussed on pages 11 and 12. 

The classification of the adult bee diseases is yet very unsatisfac- 
tory. 

THE CAUSES OF BEE DISEASES. 

As exciting causes of bee diseases different workers have from time 
to time suggested different agents. 

Schirach (1771) (p. 13) suggested two causes for foul brood — improper 
food as one, and a fault of the queen as a second. 

Leuckart had at first inclined to the view that the infectious foul 
brood was due to a fungus, but from his observations made in 1860 
(p. 14) he arrived at the conclusion that this was not true. 

Molitor-Muhlfeld (1868) (p. 15) attributed the cause to a parasitic 
ichneumon fly, Ichneumon apium mellificarium. 

Preuss (1868) (p. 15) and Schonfeld (1873-74) (p. 16) were inclined 
to believe that an infectious form of foul brood was due to a fungus, to 
which the former gave the name Cryptococcus alvearis. 

Cheshire (1884) (p. 21) and Cheyne (1885) (p. 34) were inclined 
to believe that foul brood was due to a bacillus, Bacillus alvei. 

The same disease which Cheshire and Cheyne studied came to the 
attention of William R. Howard in 1900 (p. 46), and he declared that 
the cause of it was a bacillus, to which he gave the name Bacillus 
milii. 

Recent work (p. 81) has proven that American foul brood has as 
an exciting cause a specific bacillus, to which the name Bacillus larvae, 
has been given. 

The writers of this bulletin believe that the causes for the other 
bee diseases have not as yet been satisfactorily demonstrated. 



IFDEX. 

Page. 

American foul brood, cause * 80-82 

description 11 

name given 75 

Aspergillus fiavus -. „ 73 

pollini, supposed cause of "pickled brood ". 42-44 

Bacillus A 51, 57 

alvei, description by Cheyne 31-33 

Harrison 49-50 

name given „ 21 

brandenburgiensis (see also Bacillus larvae). 

name given 72 

depilis, use of name 24 

gaytoni, use of name. 24 

larvae (see also Bacillus X and Bacterium X) , 

name given 77-78 

mesentericus vulgaris, identity 53-57 

milii, identity 47 

supposed cause of "black brood " 45-47 

pestiformis apis, description 87-88 

pestis 87 

thoracis, supposed connection with "black brood " 46 

X (see also Bacterium X and Bacillus larvae). 

name used 67 

Y, name used 86 

Bacterium giintheri 69-71 

X (see also Bacillus X and Bacillus larvae). 

name used 63 

Bahr, work on bee disease 64, 74 

"Black brood" {see also European foul brood). 

name given 44 

Blow-fly, experiments thereon 17, 20 

Burri, work on bee disease 64-66, 68-72 

Calliphora vomitoria, experiments thereon 17, 20 

Camphor treatment for bee disease 51 

Carbolic acid treatment for bee disease 21, 22, 40 

and tar treatment for bee disease 51 

Cheshire, work on bee disease 18-25 

and Cheyne, work on bee disease 25-29 

Cheyne, work on bee disease 29-35 

and Cheshire, work on bee disease 25-29 

Cowan 56 

Creolin treatment for bee disease 51 

Cryptococcus alvearis, supposed cause of ' ' virulent foul brood " 16, 17 

fermentum 16 

Dysentery 13 

Dzierzon, work on bee disease 18 

Erne, work on bee disease 75-76 

Eucalyptus treatment for bee disease 51 

European foul brood, description 12, 44 

name given 75 

95 



96 HISTORICAL NOTES ON BEE DISEASES. 

Page. 

Formaldehyde gas treatment for bee disease 62, 63 

Formic acid treatment for bee disease 51 

Foul brood, American. (See American foul brood.) 
European. (See European foul brood.) 

Guntheri — forms 69-71 

Harrison, work on bee disease 48-53, 56-58 

Howard (William R.), work on bee disease 41-47 

Ichneumon apium mellificarium, supposed cause of bee disease 15 

Imms, work on bee disease 79-80 

Isle of Wight disease 13 

description 79 

Lambotte, work on bee disease 53-56 

Larvae and pupae of bees used in making culture media 20, 55, 62-63, 81 

Leuckart, work on bee disease * 14 

Lortet, work on bee disease 38-39 

Maassen, work on bee disease 72-73, 78-79, 82-85, 91 

and Nithack, work on bee disease 92 

Mackenzie, work on bee disease 39-41 

McLain, work on bee disease 35-38 

Maiden, work on bee disease 87-89, 92-93 

Molitor-Muhlfeld, work on bee disease 14-15 

Moore and White, work on bee disease 58-61 

Musca vomitoria. (See Calliphora vomitoria.) 

Naphthalene treatment for bee disease 51 

Naphthol-beta treatment for bee disease 39, 40, 51 

"New York bee disease" (see also European foul brood). 

name given 44 

Nithack and Maassen, work on bee disease 92 

"Nonstinking foul brood," same as American foul brood . 71 

Nosema apis, name given 89 

Paralysis 13 

Phillips, work on bee disease 75, 82 

"Pickled brood," description 12 

name given 42 

Pieris rapse . ( See Pontia rapse . ) 

Pontia brassicse, experiments thereon 17 

rapse, experiments thereon 17 

Preuss, work on bee disease 15-16 

Salicylic acid treatment for bee disease 40, 51 

Schirach, work on bee disease 13-14 

Schonfeld, work on bee disease 16-17 

"Sour brood," 68 

same as European foul brood 71 

Spirochete apis, name given 72 

"Stinking foul brood," same as European foul brood. 71 

"Stone brood" 73 

Streptococcus apis, description 83 

name given 78 

Thymol treatment for bee disease 51 

White, work on bee disease 61-63, 66-67, 76-78, 80-82, 85-87 

White and Moore, work on bee disease 58-61 

Wilson, work on bee disease 67-68 

"X brood" (see also American foul brood). 

name used 63 

Zander, work on bee disease 89-90, 93 

O 

LE N '12 



